A lead inspector at Electro Tech, an electronics assembly shop, wants to convince management that it takes longer, on a per-component basis, to inspect large devices with many components than it does to inspect small devices because it is difficult to keep track of which components have already been inspected. To prove her point, she has collected data from the last 25 devices. A portion of the data is shown in the accompanying table.

Number of ComponentsInspection Time

on Device..................................(seconds)

32..........................................................84

13..........................................................49

⋮...............................................................⋮

23..........................................................70

a. Create a scatterplot of the data. Does the lead inspector's claim seem credible?

b. Estimate the linear, quadratic, and cubic regression models. Evaluate each model in terms of variable significance and adjusted R 2. Which model provides the best fit?

c. Use the best model to predict the time required to inspect a device with 35 components