#Read in the data set that contains 28 observations and a response variable y with nine predictors x1, x2, . . . ,x9

#a) use the olsrr package to perform Best Subset Regression for each k from 1 to 9

#Use aic as the model selection criterion for the following stepwise regressions

#b) perform forward stepwise regression using the option 'details=TRUE'

#c) perform backward stepwise regression using the option 'details=TRUE'

#d) perform sequential (both directions) stepwise regression using the option 'details=TRUE'

There is no need to plot the results.