Question

Q 3

Are employees who work more hours per week less satisfied with their job? Data was collected from a random sample of 22 employees at a company on the following variables:

Job satisfaction (measures 0 to 100)

Total hours worked per week

	Coefficients	Standard Error
intercept	120.7223	16.8721
X variable 1	-1.2033	0.3188

(a)Construct a 95% confidence interval estimate of the population mean job satisfaction for employees who works 55 hours per week. The sample mean total hours worked per week was 51.1818 and the sample standard deviation was 13.7517. please show your working to support your answer.

(b)Below is the residual diagnostic plot (residual versus fitted values) and histogram of the residuals for the simple linear regression model. Comment on whether the required assumptions for the simple linear regression model have met by the data. Give reasons for your answer.

For any violations of the assumptions, suggest how you can modify the model so that the required assumptions are satisfied

Histogram of residuals Residual diagnostic plot 4 3 0 10 20 30 . Frequency 2 -20 OD -40 -20 20 10 20 30 40 50 60 70 80

(c)

Answer 1