Questions: 1. Make sure your Student Engagement in Statistics.csv file is in the folder where you are saving your R files, which should be your working directory. Check your working directory by using: a. getwd()
getwd()
## [1] "/cloud/project/Stats"
install.packages("readr")
## Installing package into '/cloud/lib/x86_64-pc-linux-gnu-library/4.5'
## (as 'lib' is unspecified)
library(readr)
hw9 <- read_csv("Student Engagement in Statistics (2).csv")
## Rows: 82 Columns: 52
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (1): Q11_10_TEXT
## dbl (51): ID, ExamAnxiety, AskHelpAnxiety, InterpretAnxiety, TotalStatAnxiet...
##
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
hw9
Question: I am interested in seeing if my student’s ability to ask for help is impacted by their self-efficacy (e.g, a person’s belief in their ability to complete a task or achieve a goal). To test this, I decide to run a correlation to test the association, strength and direction between the two variables. Once I know this, I want to be able to predict their “ask for help” anxiety based on their self-efficacy. To do this, we create a regression line that best fits the data we observed. 3. Inside a chunk: (1 point for 3 and 3a) install.packages(“car”) install.packages(“psych”) a. Inside the chunk, call the libraries (you can copy and paste the following lines): library(psych) library(car)
install.packages("car")
## Installing package into '/cloud/lib/x86_64-pc-linux-gnu-library/4.5'
## (as 'lib' is unspecified)
install.packages("psych")
## Installing package into '/cloud/lib/x86_64-pc-linux-gnu-library/4.5'
## (as 'lib' is unspecified)
library(psych)
library(car)
## Loading required package: carData
##
## Attaching package: 'car'
## The following object is masked from 'package:psych':
##
## logit
plot(hw9$AskHelpAnxiety, hw9$SelfEfficacy)
5.What trend or observed pattern do you see in your plot: (no
correlation, curvilinear, positive or negative linear correlation)
Negative linear correlation 6. Check your work using the scatterplot()
function
scatterplot(hw9$AskHelpAnxiety,hw9$SelfEfficacy)
7.State the null and research hypothesis for the correlation Null: There
is no linear relationship between AskHelpAnxiety and SelfEfficacy in the
population. Research: There is a linear relationship between
AskHelpAnxiety and SelfEfficacy in the population. 8. Run the
correlation between the AskHelpAnxiety and SelfEfficacy using the cor()
function Your R code: cor(x= hw9\(SelfEfficacy, y= hw9\)AskHelpAnxiety)
cor(x= hw9$SelfEfficacy, y= hw9$AskHelpAnxiety)
## [1] -0.2308105
corr.test(x = hw9$AskHelpAnxiety, y = hw9$SelfEfficacy)
## Call:corr.test(x = hw9$AskHelpAnxiety, y = hw9$SelfEfficacy)
## Correlation matrix
## [1] -0.23
## Sample Size
## [1] 82
## These are the unadjusted probability values.
## The probability values adjusted for multiple tests are in the p.adj object.
## [1] 0.04
##
## To see confidence intervals of the correlations, print with the short=FALSE option
We reject the null hypothesis because the p-value (0.04) is less than the significance level of 0.05, indicating that the negative correlation between AskHelpAnxiety and SelfEfficacy is statistically significant. 11. Write a sentence interpreting the correlation The correlation of r = −0.23 indicates a weak negative relationship, meaning that as AskHelpAnxiety increases, SelfEfficacy tends to slightly decrease. 12. Now I want you to predict their “ask for help” anxiety based on their self-efficacy. Run a linear regression.
reg<-lm(formula= AskHelpAnxiety ~ SelfEfficacy, data= hw9)
reg
##
## Call:
## lm(formula = AskHelpAnxiety ~ SelfEfficacy, data = hw9)
##
## Coefficients:
## (Intercept) SelfEfficacy
## 17.2269 -0.1035
summary(reg)
##
## Call:
## lm(formula = AskHelpAnxiety ~ SelfEfficacy, data = hw9)
##
## Residuals:
## Min 1Q Median 3Q Max
## -4.6035 -1.2246 -0.1553 1.2318 5.2577
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 17.22691 1.48916 11.568 <2e-16 ***
## SelfEfficacy -0.10353 0.04879 -2.122 0.037 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.203 on 80 degrees of freedom
## Multiple R-squared: 0.05327, Adjusted R-squared: 0.04144
## F-statistic: 4.502 on 1 and 80 DF, p-value: 0.03696