The managing director of a real estate company wanted to study why certain branches of the company outperform others. First, she felt that the key variables in determining total annual sales $($in $ million$)$ were the advertising budget $($in $$000$s$)$ and the number of sales agents. She took a sample of $15$ branches $($and you will be asked in question $[$a$].,$ to analyse the data to get this first summary output for her$).$ Later on she added a third variable, the average number of years of experience in the real estate business for each branch, and analysed the data to get this second summary output. The data can be found in the $$Q$1$data$$ sheet of the Excel file on Canvas Week $7.$ The following variables are included $($in two steps$)$: