install.packages(“readxl”) # for reading Excel files library(readxl) # load the readxl package

Load the Excel file into R

data <- read_excel(“Class Exercise 15_TireRatings.xlsx”)

visualize data table to see if it is loaded

head(data) getwd() # run the logistic regression model model <- glm(Purchase ~ Wet + Noise, data = data, family = binomial)

Display the model coefficients

summary(model)

check the p-values for significance of Wet and Noise

summary(model) # calculate mcfadden mcfadden_r_squared <- 1 - (model\(deviance / model\)null.deviance) mcfadden_r_squared # predict prob for Wet = 8 and Noise = 8 probability_8_8 <- predict(model, newdata = data.frame(Wet = 8, Noise = 8), type = “response”) probability_8_8 # predict prob for Wet = 7 and Noise = 7 probability_7_7 <- predict(model, newdata = data.frame(Wet = 7, Noise = 7), type = “response”) probability_7_7