Question

firm administers a test to sales trainees before they go into the field. The management of the firm is interested in determining the relationship between the test scores and the sales made by the trainees at the end of the year in the field. The following data were collected for 8 sales personnel who have been in the field one year.

Salesperson number	Test scores (t)	Number of units sold (s)
1	2.5	94
2	3.7	140
3	2.4	85
4	4.5	180
5	2.6	100

a) Find the linear regression line that could be used to predictsales from trainee test scores.

b) Estimate y if x= 5.6

c) Find correlation co-efficient of co-efficient of determinationand interpret your result.

d) Plot Scatter diagram and regression line on one page.

e) Find standard error.

Answer 1

(c) Interpret results: From the correlation coefficient value, we can say that the test scores and the no. of units sold are highly correlated. Also, from the r-squared value, we can say that 99.34% of the total variation in the no. of units sold can be explained due to the linear regression on test scores.

(d) The scatter plot and regression line is given below.