Instructions

The second lab assignment is due by 2 PM on Sunday, January 26, 2020. You will respond to questions in this script. You will write corresponding R code in a code chunk for each question. Make sure to clearly annotate all of your code. You will submit this completed R Markdown script and a PDF rendered version of it to D2L by the due date and time.

Start by creating a folder for this lab assignment. You should treat each lab and exam assignment as an R Project. First, create a folder named Lab_3 on your computer to save all relevant files for this lab assignment. Go to the File menu in RStudio, select New Project…, choose Existing Directory, go to your Lab_3 folder to select it as the top-level directory for this R Project.

You should create three additional sub-folders named Scripts, Data, and Plots. You should store this script in the Scripts folder, the data for this lab assignment in the Data folder, and any requested plots in the Plots folder.

Load Libraries

We load the libraries we need for this script. If your computer did not already install these packages, then you need to install them first. To install packages, you can either:

  1. type in your Console window install.packages(“here”), or
  2. select the Tools menu option followed by Install Packages….
### Load libaries for use in current working session
## Library "here" for workflow
library(here)

## tidyverse for data manipulation and plotting
# Loads eight different libraries simultaneously
library(tidyverse)

## broom to extract output cleanly from many statistical models including "lm"
library(broom) 

## knitr to produce pleasing tables
library(knitr) 

## olsrr for regression diagnostics
library(olsrr)
library(reshape2)
library(plotly)
library(ggpubr)

Load Data

We load the facebook_likes.RData and the students.RData from the Data project directory folder.

## Load data via the here function
load(here("Data", "students.RData"))

Question 1

Working from students, create a new data frame named, sel_stud, consisting of only the complete cases for the variables proc, consc, neuro, extra, intell, and agree. Answer and execute the following:

(a). Estimate the additive unstandardized multiple regression model where the Big 5 of personality predict procrastination (proc). Name the model: mod. Print the coefficients to a kable table. What are the regresion coefficients for consc and agree?

\(\color{blue}{\text{-0.3960627, 0.0625336}}\)

(b). Produce a separate scatterplot between each of the Big 5 of personality and procrastination. Include a 80% neighborhood loess line for each scatterplot. Either produce five separate plots, or, as a challenge, create a single facet_wrap plot (Hint: One method involves restructuring the data to long format). Assess the linearity of the relationships between the Big 5 of personality and procrastination. Describe what you see in the plots.

\(\color{blue}{\text{For (proc~consc), the relationship seems negative as the line goes down. For (proc~neuro), the relationship is positive. The other relationships look negative, and all the relationships do not look strong. The outlier exit on all the plots, which need to be examined by using Residuals vs Leverage to examine.}}\)

### Q1
sel_stud <- students %>%
  select(proc, consc, neuro,extra,intell, agree)

### Q1_a
mod <- lm(proc ~ consc + neuro + extra + intell + agree, data = sel_stud)
kable(coef(mod))
x
(Intercept) 3.2757114
consc -0.3960627
neuro 0.2336395
extra -0.0662914
intell -0.0551294
agree 0.0625336
### Q2_b
p1 <- ggplot(data = sel_stud, mapping = aes(x = consc, y = proc)) +
  ## Point geomtry
  geom_point() +
  ## loess line with 10% neighborhood
  geom_smooth(method = "loess", se = FALSE, 
              span = 0.1, color = "red") +
  ## loess line with 25% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.25, color = "green") +
  ## loess line with 80% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.8, color = "blue")

p2 <- ggplot(data = sel_stud, mapping = aes(x = neuro, y = proc)) +
  ## Point geomtry
  geom_point() +
  ## loess line with 10% neighborhood
  geom_smooth(method = "loess", se = FALSE, 
              span = 0.1, color = "red") +
  ## loess line with 25% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.25, color = "green") +
  ## loess line with 80% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.8, color = "blue")

p3 <-ggplot(data = sel_stud, mapping = aes(x =extra, y = proc)) +
  ## Point geomtry
  geom_point() +
  ## loess line with 10% neighborhood
  geom_smooth(method = "loess", se = FALSE, 
              span = 0.1, color = "red") +
  ## loess line with 25% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.25, color = "green") +
  ## loess line with 80% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.8, color = "blue")

p4 <-ggplot(data = sel_stud, mapping = aes(x =intell, y = proc)) +
  ## Point geomtry
  geom_point() +
  ## loess line with 10% neighborhood
  geom_smooth(method = "loess", se = FALSE, 
              span = 0.1, color = "red") +
  ## loess line with 25% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.25, color = "green") +
  ## loess line with 80% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.8, color = "blue")

p5 <-ggplot(data = sel_stud, mapping = aes(x =agree, y = proc)) +
  ## Point geomtry
  geom_point() +
  ## loess line with 10% neighborhood
  geom_smooth(method = "loess", se = FALSE, 
              span = 0.1, color = "red") +
  ## loess line with 25% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.25, color = "green") +
  ## loess line with 80% neighborhood
  geom_smooth(method = "loess", se = FALSE,
              span = 0.8, color = "blue")

figure <- ggarrange(p1, p2, p3, p4, p5, labels = c("A", "B", "C","D","E"),
                    ncol = 3, nrow = 2)
## Warning: Removed 18 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 5.0187
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.26875
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning: Computation failed in `stat_smooth()`:
## NA/NaN/Inf in foreign function call (arg 5)
## Warning: Removed 18 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 3.5
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.25
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning: Removed 18 rows containing non-finite values (stat_smooth).
## Warning: Removed 18 rows containing missing values (geom_point).
## Warning: Removed 18 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 5.0175
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.5175
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 3.6022e-017
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning: Computation failed in `stat_smooth()`:
## NA/NaN/Inf in foreign function call (arg 5)
## Warning: Removed 18 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 3.25
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.25
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning: Removed 18 rows containing non-finite values (stat_smooth).
## Warning: Removed 18 rows containing missing values (geom_point).
## Warning: Removed 17 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 5.0175
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.5175
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 5.7155e-017
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning: Computation failed in `stat_smooth()`:
## NA/NaN/Inf in foreign function call (arg 5)
## Warning: Removed 17 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 3.5
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.25
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning: Removed 17 rows containing non-finite values (stat_smooth).
## Warning: Removed 17 rows containing missing values (geom_point).
## Warning: Removed 17 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 5.015
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.515
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning: Computation failed in `stat_smooth()`:
## NA/NaN/Inf in foreign function call (arg 5)
## Warning: Removed 17 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 3.5
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.25
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning: Removed 17 rows containing non-finite values (stat_smooth).
## Warning: Removed 17 rows containing missing values (geom_point).
## Warning: Removed 20 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 5.02
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.27
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger

## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : zero-width neighborhood. make span bigger
## Warning: Computation failed in `stat_smooth()`:
## NA/NaN/Inf in foreign function call (arg 5)
## Warning: Removed 20 rows containing non-finite values (stat_smooth).
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at 3.75
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.25
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 0
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : There are other near singularities as well. 0.0625
## Warning: Removed 20 rows containing non-finite values (stat_smooth).
## Warning: Removed 20 rows containing missing values (geom_point).
figure

Question 2

Use a broom function to create an augmented data object named sel_stud_aug. In the augmented data object, add flag variables for the ordinary and internally and externally studentized residuals. Create a new data object named, crit_out, from sel_stud_aug.

(a). Create a boxplot showing all three types of residuals in one plot. Looking across the three types of residuals, how many unique individuals are outliers?

\(\color{blue}{\text{There is 4 outliers:73,47,10 for all residual types and 132 only for externally and internally residuals }}\)

(b). Print to kable all of the reisdual values for the individuals who are outliers. What is the internally studentized residual for individual 47? What is the ordinary residual for individual 132? What is the externally studentized residual for individual 10?

\(\color{blue}{\text{47 is outlier for the studentized residual, 132 is not outlier forthe ordinary residual,and 10 is outtlier for the externally studentized residual.}}\)

(c). Print to kable all of the individuals with an externally studentized residual greater than 3 in absolute value. Which individuals are extreme outliers?

\(\color{blue}{\text{10 and 73.}}\)

(d). Produce a plot of the internally studentized (standardized) residuals against the observation number. Which individuals are outliers with respect to the threshold of 2?

\(\color{blue}{\text{73 and -10.}}\)

(e). Produce an index plot of the leverage values with all individuals whose leverage is greater than 0.10 labelled in the plot. Which individuals have a leverage value greater than 0.10?

\(\color{blue}{\text{14,98,112 and 159.}}\)

(f). Produce a plot showing the externally studentized residuals against the leverage values. How many individuals does the plot label as extreme on residuals but not extreme on leverage? Which individuals are simultaneously extreme on residuals and leverage according to the thresholds in the plot?

\(\color{blue}{\text{11 individuals, and only one,132, which is extreme on residuals and leverages}}\)

### Q2
sel_stud_aug <- augment(mod, sel_stud)

sel_stud_aug <- sel_stud_aug %>%
## Add id variable
  rownames_to_column(var = "id") %>%
## Add externally studentized residuals and outlier flags ---
  mutate(ext_resid = rstudent(mod)) %>%
## Add outlier flags
  mutate_at(
# Select variables
    vars(.resid, .std.resid, ext_resid), 
# Create function     
         list(out = ~ if_else(
# First part of condition
                        . < quantile(., 0.25) - 1.5*IQR(.) |
# Second part of condition  
                        . > quantile(., 0.75) + 1.5*IQR(.),
# Result of condition test
                        TRUE, FALSE))) 
                        
summary(sel_stud_aug)
##       id                 proc           consc           neuro      
##  Length:169         Min.   :1.000   Min.   :1.250   Min.   :1.500  
##  Class :character   1st Qu.:2.100   1st Qu.:3.000   1st Qu.:3.000  
##  Mode  :character   Median :2.500   Median :3.750   Median :3.500  
##                     Mean   :2.465   Mean   :3.587   Mean   :3.439  
##                     3rd Qu.:2.900   3rd Qu.:4.000   3rd Qu.:4.000  
##                     Max.   :3.700   Max.   :5.000   Max.   :5.000  
##      extra           intell          agree          .fitted     
##  Min.   :1.500   Min.   :2.000   Min.   :1.000   Min.   :1.496  
##  1st Qu.:3.250   1st Qu.:3.250   1st Qu.:3.500   1st Qu.:2.234  
##  Median :3.500   Median :3.750   Median :4.000   Median :2.459  
##  Mean   :3.571   Mean   :3.652   Mean   :3.913   Mean   :2.465  
##  3rd Qu.:4.000   3rd Qu.:4.000   3rd Qu.:4.250   3rd Qu.:2.678  
##  Max.   :5.000   Max.   :5.000   Max.   :5.000   Max.   :3.309  
##     .se.fit            .resid               .hat              .sigma      
##  Min.   :0.03869   Min.   :-1.364671   Min.   :0.007513   Min.   :0.4345  
##  1st Qu.:0.06261   1st Qu.:-0.285060   1st Qu.:0.019673   1st Qu.:0.4458  
##  Median :0.07840   Median : 0.007652   Median :0.030845   Median :0.4473  
##  Mean   :0.08030   Mean   : 0.000000   Mean   :0.035503   Mean   :0.4464  
##  3rd Qu.:0.09269   3rd Qu.: 0.212483   3rd Qu.:0.043115   3rd Qu.:0.4477  
##  Max.   :0.19804   Max.   : 1.363473   Max.   :0.196828   Max.   :0.4478  
##     .cooksd            .std.resid          ext_resid         .resid_out     
##  Min.   :3.000e-08   Min.   :-3.077597   Min.   :-3.161367   Mode :logical  
##  1st Qu.:2.584e-04   1st Qu.:-0.643433   1st Qu.:-0.642273   FALSE:166      
##  Median :1.707e-03   Median : 0.017295   Median : 0.017242   TRUE :3        
##  Mean   :6.275e-03   Mean   : 0.001597   Mean   : 0.002185                  
##  3rd Qu.:8.290e-03   3rd Qu.: 0.479938   3rd Qu.: 0.478802                  
##  Max.   :8.874e-02   Max.   : 3.085494   Max.   : 3.169981                  
##  .std.resid_out  ext_resid_out  
##  Mode :logical   Mode :logical  
##  FALSE:165       FALSE:165      
##  TRUE :4         TRUE :4        
##                                 
##                                 
## 
### Restructure data for plotting
## Choose data
crit_out <- sel_stud_aug %>%
  ## Select variablesadditive
  select(id, .resid, .std.resid, ext_resid,
         .resid_out, .std.resid_out, ext_resid_out) %>%
  ## Make data long format
  pivot_longer(cols = c(.resid, .std.resid, ext_resid),
               names_to = "resid_type", values_to = "resid_val")


### Q2a

### Boxplot of residuals
## Choose data and mapping
ggplot(data = crit_out, mapping = aes(x = resid_type, y = resid_val, fill = resid_type)) +
  ## Add boxplot
  geom_boxplot() +
  ## Add text label
  geom_text(aes(label = if_else(ext_resid_out, id, "")), size = 3, hjust = -0.5) +
  ## Add points
  geom_jitter(width = 0.01, alpha = 0.2) 

### Q2b
crit_out %>% 
  ## Filter for relevant variable
  filter_at(vars(.resid_out, .std.resid_out, ext_resid_out),
            any_vars(.)) %>%
  ## Print
  kable(caption = "Outlier Residuals")
Outlier Residuals
id .resid_out .std.resid_out ext_resid_out resid_type resid_val
10 TRUE TRUE TRUE .resid -1.364671
10 TRUE TRUE TRUE .std.resid -3.077597
10 TRUE TRUE TRUE ext_resid -3.161367
47 TRUE TRUE TRUE .resid 1.011369
47 TRUE TRUE TRUE .std.resid 2.278706
47 TRUE TRUE TRUE ext_resid 2.308777
73 TRUE TRUE TRUE .resid 1.363473
73 TRUE TRUE TRUE .std.resid 3.085494
73 TRUE TRUE TRUE ext_resid 3.169981
132 FALSE TRUE TRUE .resid 0.935909
132 FALSE TRUE TRUE .std.resid 2.208187
132 FALSE TRUE TRUE ext_resid 2.235088
### Q2c

### Identify large outliers
## Choose data
crit_out %>%  
  ## Filter on externally studentized residuals
  filter(resid_type == "ext_resid", abs(resid_val) >= 3) %>%
  ## Place in table
  kable(caption = "Extreme Residuals")
Extreme Residuals
id .resid_out .std.resid_out ext_resid_out resid_type resid_val
10 TRUE TRUE TRUE ext_resid -3.161367
73 TRUE TRUE TRUE ext_resid 3.169981
### Q2d
ols_plot_resid_stand(mod)

### Q2e

### Create index plot
## Choose data and mapping
ggplot(data = sel_stud_aug, mapping = aes(x = as.numeric(id), y = .hat)) +
  ## Add boxplot
  geom_point() +
  ## Add text label
  geom_text(aes(label = if_else(.hat > 0.10, id, "")), size = 3, hjust = -0.10) +
  ## Labels
  xlab("Index")

### Q2f

ols_plot_resid_lev(mod)

Question 3

Using mod, answer and execute the following:

(a). Plot the dfbetas for mod. For agreeableness, how many individuals have a DfBetas value greater than the threshold?

\(\color{blue}{\text{8 individuals.}}\)

(b). Print all of the DfBetas values to kable. For which predictor, does individual 21 have the highest DfBetas absolute value? Does individual 137 or 171 have a higher DfBetas absolute value for conscientiousness?

\(\color{blue}{\text{Yes, there are. 137 =-0.08, 171 = -0.04, 21=0.02.}}\)

(c). Plot the dffits for mod. Which individual has a DfFits value greater than the negative threshold?

\(\color{blue}{\text{Type your responses inside these curly braces. Note: This is LaTeX syntax.}}\)

(d). Print all of the DfFits values to kable. How much does the standardized fitted value change in absolute terms for individual 184?

\(\color{blue}{\text{0.3.}}\)

(e). Plot the Cook’s distance for mod. Does individual 50 have a normal Cook’s distance value?

ols_plot_cooksd_bar(mod)

\(\color{blue}{\text{It does.}}\)

(f). Does any individual have an abnormal Cook’s distance value when compared to the 50th percentile of the corresponding F distribution?

\(\color{blue}{\text{Yes it does, 112,132.}}\)

### Q3a
## Plot
ols_plot_dfbetas(mod)

### Q3b
dfbetas(mod) %>%
  ## Print
  kable(caption = "DfBetas")
DfBetas
(Intercept) consc neuro extra intell agree
1 0.0916991 0.0164484 -0.1747360 0.0619060 0.0194990 -0.0699683
2 0.0046204 -0.0245262 0.0666703 -0.0240517 0.0153203 -0.0334036
3 -0.0034092 -0.0156553 0.0011157 0.0293050 0.0030304 -0.0096846
4 0.0192188 0.0752026 0.0156769 0.0661697 -0.0344385 -0.1118863
5 0.0324024 0.1875191 -0.0073264 -0.1300185 0.0177724 -0.0520453
6 0.0076125 0.0130656 -0.0294374 -0.0028897 0.0097648 -0.0034049
10 -0.0106754 0.0163659 -0.0189163 -0.0018012 -0.0193408 0.0282120
11 0.0041962 -0.0137750 -0.0005362 0.0068558 0.0085199 -0.0082897
12 0.0108148 -0.0089805 0.0054920 -0.0325887 0.0005453 0.0151827
13 -0.1675288 -0.0986436 -0.0144000 0.1845693 0.1454929 -0.0109469
14 -0.0709108 0.1066801 0.2603897 -0.0004869 -0.0251371 -0.0965383
15 0.0883792 0.0130009 -0.0575471 -0.0086609 -0.1296041 0.0150627
16 0.0031764 -0.0152524 -0.0194597 0.0211339 -0.0153180 0.0193436
17 0.0819071 -0.2195538 -0.0959014 -0.0691597 0.1601458 0.0135305
18 -0.0473368 -0.0503867 -0.0093636 0.0468902 0.0237098 0.0514754
19 0.1153612 0.0631714 -0.2938882 -0.2429811 -0.0152649 0.2083452
20 0.0016247 0.0309399 -0.0277288 -0.0140669 -0.0037426 0.0073801
21 0.0216065 -0.0720508 0.0774789 0.0878246 -0.0338592 -0.0772344
23 -0.0292196 0.0631163 0.0355604 0.0134684 -0.0944597 0.0439895
24 0.0013950 0.0082229 -0.0097480 0.0199819 -0.0128096 -0.0016081
25 -0.0258634 -0.0782962 0.0446126 0.0732549 -0.0954553 0.0634686
26 0.0120887 -0.0207778 0.0199928 -0.0257978 -0.0079651 0.0102349
28 0.0771904 -0.0428347 -0.1435777 0.1281056 0.0436641 -0.1349246
29 0.0527717 -0.0361563 0.0634054 -0.2371055 0.0190790 0.0601242
30 0.0448089 0.0320978 0.0204129 -0.0193252 -0.1258107 0.0413318
31 0.0579636 0.0158029 -0.0893342 0.1143603 -0.0424918 -0.0649501
32 0.0000613 -0.0000055 -0.0000766 0.0001143 0.0001860 -0.0002487
33 0.0624726 -0.0316201 -0.0372075 -0.0100160 0.0056694 -0.0398072
35 0.0408876 -0.0602160 -0.0351577 0.0984319 -0.0876241 0.0010269
36 -0.0007780 0.0017989 -0.0025846 0.0040189 0.0046411 -0.0052625
37 -0.0073234 -0.0314228 -0.0159010 -0.0027965 0.0365926 0.0057175
38 -0.0505138 0.0046559 -0.0071353 0.0481885 0.0788189 -0.0441858
39 -0.0484125 -0.1207637 0.1272944 0.0415323 0.0091255 0.0091564
40 -0.0236084 0.0155646 -0.0391648 0.0540543 -0.0020685 0.0023756
41 0.0046024 -0.0012839 0.0007542 0.0048173 -0.0106180 -0.0007294
42 -0.3002652 -0.0345826 0.2599355 -0.1903794 0.2818705 0.1715560
43 -0.0363501 -0.0290638 0.0171749 0.0178261 0.0257301 0.0230563
44 -0.0256741 -0.0269302 0.0310784 0.0184426 0.0240325 0.0009745
45 -0.0775631 0.1542689 0.1505686 -0.0686786 -0.1022525 0.0656977
46 -0.0637960 0.0029842 0.0120783 0.0721715 0.0186550 0.0072432
47 0.0194421 -0.1177522 0.0837814 -0.0918904 -0.0808177 0.1568888
48 0.0463345 -0.0292650 -0.0712254 -0.0387777 0.0718759 -0.0404450
49 0.0001408 0.0000866 -0.0011284 -0.0010959 -0.0000647 0.0015464
50 0.0000763 0.0033585 -0.0010265 0.0023634 -0.0028785 -0.0013396
51 -0.0862806 -0.0430290 0.0396335 0.0533065 0.0264278 0.0620215
52 0.0135053 -0.0194641 0.0073275 0.0047821 0.0060534 -0.0171807
53 0.0249749 -0.0905151 -0.0240724 -0.0464027 -0.0537298 0.1460968
54 -0.0177604 -0.0089017 0.0193896 0.0084127 0.0273631 -0.0113796
55 -0.0476414 0.0904997 -0.0855082 -0.1337873 0.0447294 0.1426646
57 -0.1528101 0.0056493 0.1877199 -0.0731514 0.1796728 -0.0396283
58 -0.0004553 -0.0040768 -0.0028159 -0.0048333 0.0069196 0.0019126
59 0.1038025 -0.0294064 -0.0698610 -0.0356557 0.0568527 -0.0801809
61 -0.0001657 0.0025463 0.0080147 -0.0005310 -0.0023897 -0.0023899
62 -0.0254236 -0.0248524 0.0636303 0.0141162 -0.0091469 -0.0070612
63 -0.0790341 -0.1645025 0.1101008 0.0074066 0.1087674 0.0461618
65 0.0137731 0.0073728 -0.0256174 0.0010064 0.0147178 -0.0227353
66 0.0191986 0.0786979 -0.0161519 -0.0497805 0.0897508 -0.1137801
67 0.0939603 -0.0724442 -0.0391238 0.1347793 -0.0345406 -0.1196153
68 0.0202062 -0.0056109 -0.0118630 -0.0091256 -0.0073239 -0.0007623
69 -0.0268535 0.0204200 0.0994618 -0.0391491 -0.0707729 0.0602468
70 0.0046572 0.0147912 0.0030215 -0.0164030 -0.0100070 0.0019216
71 -0.0245359 0.0153734 0.0334091 0.0184340 -0.0324351 0.0106490
73 0.1500678 -0.0490171 -0.0026130 -0.1636882 -0.0717532 0.0352160
74 -0.0702226 -0.0247016 0.0194800 -0.0074645 0.0361936 0.0639176
75 0.0977394 -0.0712327 -0.1586503 0.0727374 -0.0487917 -0.0100441
76 0.2498857 -0.0471890 0.0849666 -0.3137740 -0.2802243 0.1561936
77 0.0061466 -0.0177125 0.0093116 -0.0217684 0.0040074 0.0081040
78 0.0071064 -0.0126283 0.0134755 0.0080282 -0.0008809 -0.0170126
79 0.1823395 0.0650420 -0.0373099 -0.0247826 -0.0760557 -0.1614967
80 0.0749608 -0.0426804 -0.2044144 0.1505995 -0.0255454 -0.0507322
81 0.0036386 -0.0540783 -0.0318075 0.0281829 -0.0067890 0.0288122
82 -0.2725235 0.1799980 0.0863332 0.2331493 -0.1064800 0.1244460
83 -0.0104983 0.1890940 -0.0802088 -0.1338927 0.2533251 -0.1428840
84 0.0144365 -0.0131778 0.0327320 -0.0218587 -0.0017552 -0.0097336
85 -0.0562685 -0.0987678 0.0512886 -0.0543286 0.1695217 -0.0179692
86 0.0198723 -0.0616580 0.0611159 0.0535152 -0.2355914 0.1279683
88 -0.0070907 -0.0266254 0.0024425 -0.0183205 0.0106728 0.0316892
90 0.0008038 0.0044130 -0.0026250 0.0022723 -0.0033752 -0.0000964
93 0.0033161 -0.0047310 -0.0029849 0.0047237 0.0034643 -0.0045383
94 -0.0413984 0.0594173 -0.1072458 0.0759416 0.1146585 -0.0872870
95 -0.0123059 0.2162678 -0.0796907 0.0726153 -0.0130201 -0.1285243
96 0.0205472 -0.0329327 -0.0207246 0.1079446 -0.0842311 0.0057610
97 0.0193059 -0.0001395 -0.0142103 -0.0159799 -0.0072362 0.0008955
98 -0.0122581 -0.0183967 -0.0119613 -0.0457962 0.0158358 0.0532029
100 0.0168194 -0.0386301 0.1116996 0.0212612 0.1173658 -0.1729215
101 -0.0096518 0.0004405 0.0116162 -0.0124304 -0.0038754 0.0167545
103 -0.0056298 0.0604941 -0.0052641 0.0200966 -0.0351528 -0.0037176
104 0.0101177 0.0101604 -0.0085076 -0.0032275 -0.0089625 -0.0025340
105 -0.0120513 -0.0072394 -0.0037722 0.0068219 0.0223945 -0.0036671
106 -0.0177138 -0.0300936 0.0151293 0.0474001 0.0042188 -0.0030192
107 0.0093938 -0.0024334 -0.0110761 -0.0053835 -0.0024410 -0.0012552
108 0.0543550 -0.0879932 -0.0361889 -0.0145289 -0.0562172 0.0587375
109 -0.0105785 -0.1013267 -0.1009267 0.0939734 0.0020560 0.0581243
110 -0.0131532 -0.0088127 0.0102016 -0.0018578 -0.0002927 0.0206964
112 0.0955300 0.3125445 0.1318603 0.0469046 -0.3808869 -0.1280888
113 -0.0494918 0.1209911 -0.0562042 -0.0125482 -0.0031081 0.0283469
114 0.0100673 -0.0005327 -0.0087894 -0.0053880 -0.0079004 0.0046474
115 -0.0336538 -0.0894286 0.0794397 -0.0352554 -0.0544949 0.1217216
116 -0.0016685 0.0024495 -0.0012855 0.0010602 -0.0003607 0.0011416
117 -0.0016613 -0.0106607 -0.0107462 -0.0132522 0.0155530 0.0105500
118 0.0619275 0.0164137 0.0014286 -0.0435293 -0.0425995 -0.0167692
119 -0.0757866 0.0764484 -0.0157801 0.0407485 0.0156579 0.0095731
120 0.0003973 0.0093155 0.0013008 0.0194680 -0.0158470 -0.0069607
121 0.0748437 -0.0517205 -0.0480436 -0.0120327 -0.0039630 -0.0293752
122 -0.0764997 -0.1730316 0.1211740 0.1837866 0.0012229 -0.0198283
123 0.0074829 -0.0332055 0.0147482 0.0090234 -0.0185274 0.0056697
124 -0.0158817 0.0462653 0.0436106 -0.0608558 0.0751094 -0.0399493
125 0.0054319 -0.0094892 0.0114875 0.0556448 0.0144697 -0.0589260
126 0.0231219 0.0301532 -0.0535520 -0.0581391 0.0336490 0.0069686
127 -0.0114440 -0.0849430 0.0392935 0.0188063 0.0195376 0.0175846
128 -0.0002737 0.0006451 0.0008802 -0.0000296 0.0009699 -0.0012512
129 0.5166166 0.0261794 -0.2399338 0.0795488 -0.1191539 -0.4892456
130 -0.0242004 -0.0468605 0.0173201 -0.0302763 0.0056112 0.0773231
131 0.0051108 -0.0266030 -0.0006665 -0.0008567 -0.0549915 0.0626474
132 0.0111690 -0.0462845 0.0186978 -0.0221056 0.0325576 -0.0051379
134 0.0162744 0.0049406 -0.0448622 -0.0299622 -0.0147207 0.0427651
135 -0.0635136 0.0487950 0.0180368 -0.0522656 -0.0450212 0.1124485
136 -0.0050605 -0.0068624 0.0035868 -0.0048910 0.0056176 0.0066664
137 -0.0769517 -0.1330472 -0.0208423 0.0158162 0.1228560 0.0643564
138 -0.0461150 0.1824054 -0.0970266 0.0475175 0.0593203 -0.0952005
139 -0.0269528 0.0117461 0.0182957 0.0222438 -0.0013198 0.0021004
141 -0.0406853 -0.0271686 0.0359298 -0.0104534 0.0099522 0.0411885
142 0.0027230 0.0418498 0.0006213 0.0001623 0.0099771 -0.0436984
143 -0.0196936 0.0251492 0.0454753 0.0531176 -0.0056722 -0.0602928
144 -0.0691921 -0.0224073 0.0253660 -0.0001907 0.0508123 0.0506702
145 0.0003188 0.0002832 0.0013612 0.0026848 -0.0007236 -0.0031361
146 0.0001686 -0.0280884 -0.0160267 0.0201553 0.0093246 0.0057908
147 -0.0023570 0.0007717 -0.0010139 0.0055778 -0.0024680 0.0002661
148 -0.0276576 -0.0520413 -0.0053397 0.0818997 -0.0239785 0.0180437
149 0.0311682 -0.0419826 -0.0224228 0.0169672 -0.0296541 0.0042000
150 0.0037455 0.0113169 -0.0068260 0.0180222 -0.0128459 -0.0087846
151 -0.1452054 0.0627884 0.3324096 -0.3378154 0.5180420 -0.2256175
152 -0.0033046 -0.0034729 0.0077705 0.0065246 -0.0000448 -0.0041240
154 0.0209933 -0.0089205 -0.0445242 -0.0081782 -0.0194492 0.0256807
155 -0.0635599 -0.1013799 -0.0837699 0.1316884 -0.0189438 0.1360574
156 0.0093367 0.0246487 -0.0469238 0.0236225 -0.0301873 0.0123579
157 0.0504220 0.0066146 -0.0663032 -0.0398577 0.0118713 -0.0041424
158 0.0406849 0.1074076 -0.2044723 0.1029358 -0.1315426 0.0538502
159 0.0073378 0.0017790 0.0002686 -0.0037301 -0.0059896 -0.0019191
160 -0.1029525 0.1933510 -0.0958654 -0.0103593 0.0543369 0.0490086
161 0.1712797 -0.1262293 0.1798796 -0.1210654 -0.1376336 -0.0556239
162 -0.0236787 0.0926248 -0.1154239 -0.2107611 0.1777667 0.0298500
163 0.0276234 0.0121937 -0.0367689 -0.0247064 -0.0087155 0.0094627
165 -0.0545902 -0.0345224 0.1135415 -0.0381446 -0.0393929 0.0785777
166 -0.1075809 -0.0913348 0.0697594 -0.0073123 0.0034187 0.1476033
167 0.0359556 -0.0037279 -0.0176798 0.0081242 0.0088118 -0.0527126
168 -0.0609552 0.0387443 -0.0111019 0.0338583 0.0629333 -0.0257226
169 -0.1205580 0.0963845 0.0499941 -0.0542842 0.1902825 -0.0719245
170 0.0002329 -0.0141493 0.0218903 0.1554264 -0.1848720 0.0472419
171 -0.0375237 0.0109367 -0.0223711 -0.0147383 -0.0048542 0.0641092
172 0.0177076 0.1670595 0.0293749 -0.0044601 -0.1699529 -0.0075969
173 -0.0448252 0.0701561 -0.1566682 0.1511330 0.1107670 -0.0829859
174 -0.0354088 -0.0025814 0.0107087 0.0480941 -0.0095401 0.0166723
175 -0.0369480 -0.0316014 0.0264468 0.0032362 0.0692008 -0.0222686
176 -0.0017857 0.0088511 0.0047302 0.0002239 0.0004438 -0.0060245
177 0.0134110 0.0386433 -0.0218868 -0.0244459 -0.0100562 -0.0063052
178 0.0259451 -0.0824358 0.1305616 -0.1503829 0.1358014 -0.0773410
179 0.0102129 -0.0388816 -0.1303180 -0.0643274 0.0217488 0.1054761
180 0.3786729 -0.0209525 -0.1564802 -0.1620285 -0.1433651 -0.1247745
181 -0.0410543 0.0553495 0.1904473 0.0457838 -0.0625211 -0.0673250
182 -0.0223583 0.0228964 0.0361298 -0.0092754 0.0015403 0.0028368
183 0.0037682 -0.0079277 -0.0219488 0.0094428 -0.0102224 0.0178109
184 -0.1021706 0.2137903 0.0362059 0.1535721 -0.1218155 -0.0473435
185 -0.0011039 -0.0063465 0.0038114 0.0049581 -0.0017058 0.0017787
186 0.0605673 -0.1026823 -0.0715686 0.0675307 -0.1104075 0.0605846
187 -0.0607952 0.0314073 0.0876815 -0.0222904 0.0329394 0.0019830
189 -0.0005778 -0.0001136 -0.0001025 0.0005656 0.0002014 0.0003351
190 0.0017664 -0.0080781 0.0078055 0.0010061 0.0253704 -0.0228291
191 -0.0117104 0.0010870 -0.0024522 -0.0089085 0.0108910 0.0123654
### Q3c
ols_plot_dffits(mod)

dffits(mod)
##             1             2             3             4             5 
##  0.2299364656 -0.1010161800  0.0371677557 -0.1522371675  0.2833091318 
##             6            10            11            12            13 
##  0.0404897416 -0.0598686016  0.0203187792  0.0386902743 -0.3656820009 
##            14            15            16            17            18 
##  0.3432467397 -0.1943213897  0.0552365304  0.2981343028  0.1194553903 
##            19            20            21            23            24 
##  0.4526263329 -0.0473187058 -0.1799855161 -0.1276144418  0.0368208957 
##            25            26            28            29            30 
## -0.2203969526 -0.0418935399 -0.2461982303 -0.2914001588  0.1469097235 
##            31            32            33            35            36 
##  0.1948836348  0.0003927446 -0.0817910630 -0.1586449115  0.0085230988 
##            37            38            39            40            41 
## -0.0575523112 -0.1097872958 -0.1947502527 -0.0749024256 -0.0129753897 
##            42            43            44            45            46 
##  0.4621958650  0.0612672516  0.0615760154  0.2790523765  0.0974140674 
##            47            48            49            50            51 
##  0.2541909046 -0.1402464977  0.0025639610 -0.0056691688  0.1413539107 
##            52            53            54            55            57 
##  0.0331095680  0.2474742985  0.0396622308  0.2898377160 -0.3023523131 
##            58            59            61            62            63 
## -0.0107926436  0.1855432760  0.0149286531 -0.1270550903  0.2130813864 
##            65            66            67            68            69 
## -0.0392617070 -0.1795112348  0.2083161467  0.0235712346  0.1488143946 
##            70            71            73            74            75 
## -0.0298317469 -0.0673066693  0.2221748172 -0.0951652506 -0.2232951249 
##            76            77            78            79            80 
##  0.4912671332 -0.0346623192 -0.0320228247  0.2310846725 -0.2738645102 
##            81            82            83            84            85 
## -0.0860778211  0.4329362723  0.4525109579  0.0511681294 -0.2236239024 
##            86            88            90            93            94 
## -0.2931844994  0.0436893796  0.0091198827  0.0155276721 -0.2133979213 
##            95            96            97            98           100 
## -0.2577880404  0.1543361489 -0.0272862285 -0.0735594406  0.2561467094 
##           101           103           104           105           106 
## -0.0242908267  0.0948345284  0.0193940575 -0.0277933359  0.0679893126 
##           107           108           109           110           112 
## -0.0314991087 -0.1465196220 -0.2035045425  0.0299321456 -0.5365371442 
##           113           114           115           116           117 
## -0.1553368611  0.0158734797 -0.1642927873  0.0039603199 -0.0294906575 
##           118           119           120           121           122 
##  0.0867076422 -0.1169700478  0.0273052561 -0.1072864991 -0.2928782082 
##           123           124           125           126           127 
## -0.0621352477  0.1661516557  0.0860668805  0.1097354851  0.0992514580 
##           128           129           130           131           132 
##  0.0023168668  0.6097471230  0.1044780384  0.0848895110  0.0637239411 
##           134           135           136           137           138 
##  0.0735038900 -0.1535867464 -0.0130084713 -0.2181857492 -0.2423120035 
##           139           141           142           143           144 
##  0.0377725313 -0.0747305193 -0.0659814586 -0.1018057457  0.0967586005 
##           145           146           147           148           149 
## -0.0046148381  0.0441213258 -0.0087715051 -0.1409368218 -0.0915286459 
##           150           151           152           154           155 
##  0.0268003705  0.7385869824 -0.0130916217 -0.0630111993  0.3024443714 
##           156           157           158           159           160 
##  0.0660214549  0.0889664061  0.2876910922  0.0111749826  0.2898105701 
##           161           162           163           165           166 
## -0.3682226903 -0.3577695433  0.0560962721 -0.1529342509 -0.1915375086 
##           167           168           169           170           171 
## -0.0687416957 -0.1067586561 -0.2638512978  0.2521509376 -0.0961927942 
##           172           173           174           175           176 
## -0.2465901143  0.3015745288  0.0669563264 -0.1146821006  0.0131208470 
##           177           178           179           180           181 
## -0.0657778634 -0.2733092254 -0.2314444646  0.3887749858  0.2541323347 
##           182           183           184           185           186 
##  0.0591039997  0.0384421495 -0.2939768420  0.0120183408 -0.2252987033 
##           187           189           190           191 
##  0.1241116316  0.0009768099  0.0376988950 -0.0221036636
### Q3d
### DfFits
## Calculation
dffits(mod) %>%
  ## Print
  kable(caption = "DfFits")
DfFits
x
1 0.2299365
2 -0.1010162
3 0.0371678
4 -0.1522372
5 0.2833091
6 0.0404897
10 -0.0598686
11 0.0203188
12 0.0386903
13 -0.3656820
14 0.3432467
15 -0.1943214
16 0.0552365
17 0.2981343
18 0.1194554
19 0.4526263
20 -0.0473187
21 -0.1799855
23 -0.1276144
24 0.0368209
25 -0.2203970
26 -0.0418935
28 -0.2461982
29 -0.2914002
30 0.1469097
31 0.1948836
32 0.0003927
33 -0.0817911
35 -0.1586449
36 0.0085231
37 -0.0575523
38 -0.1097873
39 -0.1947503
40 -0.0749024
41 -0.0129754
42 0.4621959
43 0.0612673
44 0.0615760
45 0.2790524
46 0.0974141
47 0.2541909
48 -0.1402465
49 0.0025640
50 -0.0056692
51 0.1413539
52 0.0331096
53 0.2474743
54 0.0396622
55 0.2898377
57 -0.3023523
58 -0.0107926
59 0.1855433
61 0.0149287
62 -0.1270551
63 0.2130814
65 -0.0392617
66 -0.1795112
67 0.2083161
68 0.0235712
69 0.1488144
70 -0.0298317
71 -0.0673067
73 0.2221748
74 -0.0951653
75 -0.2232951
76 0.4912671
77 -0.0346623
78 -0.0320228
79 0.2310847
80 -0.2738645
81 -0.0860778
82 0.4329363
83 0.4525110
84 0.0511681
85 -0.2236239
86 -0.2931845
88 0.0436894
90 0.0091199
93 0.0155277
94 -0.2133979
95 -0.2577880
96 0.1543361
97 -0.0272862
98 -0.0735594
100 0.2561467
101 -0.0242908
103 0.0948345
104 0.0193941
105 -0.0277933
106 0.0679893
107 -0.0314991
108 -0.1465196
109 -0.2035045
110 0.0299321
112 -0.5365371
113 -0.1553369
114 0.0158735
115 -0.1642928
116 0.0039603
117 -0.0294907
118 0.0867076
119 -0.1169700
120 0.0273053
121 -0.1072865
122 -0.2928782
123 -0.0621352
124 0.1661517
125 0.0860669
126 0.1097355
127 0.0992515
128 0.0023169
129 0.6097471
130 0.1044780
131 0.0848895
132 0.0637239
134 0.0735039
135 -0.1535867
136 -0.0130085
137 -0.2181857
138 -0.2423120
139 0.0377725
141 -0.0747305
142 -0.0659815
143 -0.1018057
144 0.0967586
145 -0.0046148
146 0.0441213
147 -0.0087715
148 -0.1409368
149 -0.0915286
150 0.0268004
151 0.7385870
152 -0.0130916
154 -0.0630112
155 0.3024444
156 0.0660215
157 0.0889664
158 0.2876911
159 0.0111750
160 0.2898106
161 -0.3682227
162 -0.3577695
163 0.0560963
165 -0.1529343
166 -0.1915375
167 -0.0687417
168 -0.1067587
169 -0.2638513
170 0.2521509
171 -0.0961928
172 -0.2465901
173 0.3015745
174 0.0669563
175 -0.1146821
176 0.0131208
177 -0.0657779
178 -0.2733092
179 -0.2314445
180 0.3887750
181 0.2541323
182 0.0591040
183 0.0384421
184 -0.2939768
185 0.0120183
186 -0.2252987
187 0.1241116
189 0.0009768
190 0.0376989
191 -0.0221037

Question 4

Using mod, answer and execute the following:

(a). Plot the externally studentized residuals against the fitted values. Perform the Breusch_Pagan test to evaluate homoscedastisticity of residuals. What does the test result suggest about homoscedasticity of residuals?

\(\color{blue}{\text{The variance of externally studentized residuals are different.}}\)

(b). Ccompute the deciles of the fitted values. Then, compute the variance of the residuals of each of the deciles. Finally, compute the ratio of the maximum to minimum variance of the residuals across the deciles. Does the ratio indicate evidence for heteroscedasticity?

\(\color{blue}{\text{The ration is 3.6 < 10 which means there is no violation.}}\)

### Q4a
ols_plot_resid_stud_fit(mod)

ols_test_breusch_pagan(mod)
## 
##  Breusch Pagan Test for Heteroskedasticity
##  -----------------------------------------
##  Ho: the variance is constant            
##  Ha: the variance is not constant        
## 
##               Data               
##  --------------------------------
##  Response : proc 
##  Variables: fitted values of proc 
## 
##         Test Summary         
##  ----------------------------
##  DF            =    1 
##  Chi2          =    1.58885 
##  Prob > Chi2   =    0.2074905
###Q4b

#### Quantification of heteroscedasticity
### Create groups as a function of fitted values
## Choose data
homoscedast_check <- sel_stud_aug %>%
  ## Select variables
  select(.fitted, .resid) %>%
  ## Create variable
  mutate(fit_group = cut(.fitted,
                         quantile(.fitted, 
                                  probs = seq(0, 1, 0.1)), 
                         include.lowest = TRUE))

### Summarize variance across groups
## Choose data
homoscedast_check %>%
  ## Group
  group_by(fit_group) %>%
  ## Summarize variance
  summarize(fit_var = var(.resid)) %>%
  ## Ungroup
  ungroup() %>%
  ## Summarize max/min ratio
  summarize(ratio = max(fit_var)/min(fit_var))
## # A tibble: 1 x 1
##   ratio
##   <dbl>
## 1  3.59

Question 5

Using mod, answer and execute the following:

(a). Produce the empirical density plot of the externally studentized residuals. Overlay the theoretical normal distribution for these residuals. Does the plot suggest the residuals are sufficiently normally distributed?

\(\color{blue}{\text{Yes it does. It displays the normal distribution of the leptokurtic shape.}}\)

(b). Produce a Q-Q plot. Are the deviations from normality greater in the positive or negative 1-2 range of the theoretical quantiles?

\(\color{blue}{\text{It is greate in the positive.}}\)

### Q5a

### Density plot of residuals
## Choose data and mapping
ggplot(data = sel_stud_aug, mapping = aes(x = ext_resid)) +
  ## Empirical density
  geom_density(color = "blue") +
  ## Theoretical density
  stat_function(fun = dnorm, color = "red")

### Q5b

ols_plot_resid_qq(mod) 

Question 6

Calculate the tolerance and variance inflation factor for each of the predictors in mod. Are there any predictors very correlated with the other predictors?

\(\color{blue}{\text{No, there are all close to 1 in terms of tolerance and less than 10 in terms of VIF.The points fall approximately along the red line}}\)

ols_coll_diag(mod)$vif_t
## # A tibble: 5 x 3
##   Variables Tolerance   VIF
##   <chr>         <dbl> <dbl>
## 1 consc         0.867  1.15
## 2 neuro         0.967  1.03
## 3 extra         0.869  1.15
## 4 intell        0.864  1.16
## 5 agree         0.798  1.25