In a manufacturing procedure the assembly line speed(feet per minute) was thought to affect number of defective parts, found throughout the inspection procedure. To test this theory, managers devised a condition in which the same batch of parts was inspected visually at the variety of line speeds. They collected the following date.
Line Speed Number of defective parts found
20 21
20 19
40 15
30 16
60 14
40 17
a. Develop the estimated regression equation which relates line speed to the number of defective parts found.
b. At a .05 level of significance, find out whether line speed and number of defective parts fourn are related.
c. Did the estimated regression equation provide a good fit to the data?
d. Make a 95% confidence interval to predict the mean number of defective parts for a line speed of 50 feet per minute.