Finger dexterity, the ability to make precisely coordinated finger movements to grasp or assemble very small objects, is important in jewelry making. Subsequently, the manufacturing manager at Gemco, a manufacturer of high-quality watches, wants to develop a regression model to predict the productivity (in watches per shift) of new employees based on dexterity. He has subjected a sample of 20 current employees to the O’Connor dexterity test in which the time required to place 3 pins in each of 100 small holes using tweezers is measured. A portion of the data is shown in the accompanying table.

Time (seconds)                       Watches per shift

513……………………………………….23

608……………………………………….19

⋮……………………………………………⋮

437……………………………………….20

a. Use Excel to estimate the model: Watches = β₀ + β₁Time + ε.

b. Interpret the coefficient of Time.

c. Explain why the y-intercept makes no practical sense in this particular problem.

d. Suppose a new employee takes 550 seconds on the dexterity test. How many watches per shift is she expected to produce?