library(readxl)
dog_and_cat_data_<- read_excel("dog and cat data .xlsx")
##Question One: Load your chosen data set into R Markdown##
##Question Two: Create a linear model "lm()" from the variables, with a continuous dependent variable##
sheltermodel<- lm(`Animals Euthanized` ~Adoptions +Fosters, data= dog_and_cat_data_)
summary(sheltermodel)
## 
## Call:
## lm(formula = `Animals Euthanized` ~ Adoptions + Fosters, data = dog_and_cat_data_)
## 
## Residuals:
##       1       2       3       4       5       6       7       8 
## -438.63  135.09  281.70 -639.13  186.85   52.47  246.64  175.01 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)   
## (Intercept) -922.8312   382.9713  -2.410  0.06089 . 
## Adoptions      0.2290     0.1164   1.966  0.10643   
## Fosters        2.8216     0.5093   5.541  0.00263 **
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 406.8 on 5 degrees of freedom
## Multiple R-squared:  0.9096, Adjusted R-squared:  0.8735 
## F-statistic: 25.17 on 2 and 5 DF,  p-value: 0.002454
##Question Three: ##
library(lmtest)
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric
library(MASS)
library(car)
## Loading required package: carData
raintest(sheltermodel)
## 
##  Rainbow test
## 
## data:  sheltermodel
## Rain = 0.76003, df1 = 4, df2 = 1, p-value = 0.6847
##not linear##
durbinWatsonTest(sheltermodel)
##  lag Autocorrelation D-W Statistic p-value
##    1      -0.3078198      2.346159   0.186
##  Alternative hypothesis: rho != 0
##not significant##
bptest(sheltermodel)
## 
##  studentized Breusch-Pagan test
## 
## data:  sheltermodel
## BP = 0.16501, df = 2, p-value = 0.9208
##not significant##
##normality of residuals##
plot(sheltermodel,which = 3)

##not normal##
##multicolinearity##
vif(sheltermodel)
## Adoptions   Fosters 
##  1.172648  1.172648
##assumption is not violated##
##Question Five: the only model that does not violate the assumptions is the multicolinearity##

##Question Six: To mitigate the assumption of linearity, you could use a log transformation to transform the variables to see if this helps it become more linear. To mitigate independence of errors, you can run a RLM or robust linear model. To mitigate heteroscedasticity, you could conduct a log transformation of the depenedent variable. To mitigate non-normality of residuals, you could use a log transformation. To mitigate multicolinearity, you could remove the strongly correlated variables##