Tem Rousos, president of Rousos Ford, believes there is a relationship between the number of new cars ...

     Problem 3     Tem Rousos, president of   Rousos Ford, believes there is a relationship between the number of new cars   sold and the number of sales people on duty. To investigate he selects a   sample of eight weeks and determines the number of new cars sold and the   number of sales people on duty for that week.            Week Sales staff (x) Cars sold (y)    1      5 53    2      5 47    3      7 48    4      4 50    5    10 58    6    12 62    7      3 45    8    11 60          a.     Determine the coefficient of correlation.   b.     Determine the coefficient of determination. Comment on the strength of the   association between the two variables.   c.     Determine the   regression equation.   d.      Interpret the regression equation. Where does the equation cross the Y-axis?   How many additional cars can the dealer expect to sell for each additional   salesperson employed?         e.      Determine the standard error of estimate.   f.        Develop a 95 percent confidence interval for all   the mean car sales for weeks when the sales staff is at 10.   g.    In   checking the work schedules for next week, Tern finds there are 10 people   scheduled. Develop a 95 percent prediction interval for the number of cars   sold next week.