A manufacturing plant receives orders for customized mechanical parts. The orders vary in size, from about 30 to 130 units. After configuring the production line, a supervisor oversees the production....

A manufacturing plant receives orders for customized mechanical parts. The orders vary in size, from about 30 to 130 units. After configuring the production line, a supervisor oversees the production. The scatterplot in Figure 5 plots the production time (in hours) versus the number of units for 45 orders.

The least squares regression line in the scatterplot (Figure 5) is

 Production Time (Hours) = 2.1 + 0.031 Number of Units

a. Interpret the intercept of the estimated line. Is the intercept visible in Figure 5?
⁴

b. Interpret the slope of the estimated line.⁵

c. Using the fitted line, estimate the amount of time needed for an order with 100 units. Is this estimate an extrapolation?
⁶

d. Based on the fitted line, how much more time does an order with 100 units require over an order with 50 units?⁷