Question

4. A substance used in biological and medical research is shipped by airfreight to users in cartons of 1,000 ampules. The data below, involving 10 shipments, were collected on the number of times the carton was transferred from one aircraft to another over the shipment route (X) and the number of ampules found to be broken upon arrival (Y). i 12345 67 89 10 X 1 02 03 1 0 2 0 Y 169 17 12 2213 8 15 19 11 (a) Plot the data. (b) Obtain the estimated simple linear regression model. (c) Plot the fitted line on the scatterplot with the data (d) Does a linear regression function appear to give a good fit here? (e) Obtain a point estimate of the expected number of broken ampules when one transfer is made. (f) Obtain the residuals. Do they sum to 0?

Answer 1

We use Excel to solve this question-

a) Please see attachments
b) The estimated simple linear regression model is,
   y^ = 10.2 + 4 * x
c) Please see attachments
d) The coefficient of determination, R square = 0.90 indicate that regression function appear to good fit here.
e) at x = 1, the expected number of broken ampules, y^ is given by,
   y^ = 10.2 + 4 * x
   y^ = 10.2 + 4 * 1
   y^ = 14.2
f) Please see attachments, Yes residuals sum to 0.