Work standards specify time, cost, and efficiency rooms for the performance of work tasks. They are typically used to monitor job performance. In the distribution centre of McCormick and Co. Inc, data were collected to develop work standards for the time to assemble or fill customer orders (Production and Inventory Management Journal, 1991). The table to the right contains data for a random sample of 9 orders.
a. Construct a scattergram for these data and interpret it.
b. Fit a least square line to these data using time as the dependent variable.
c. In general, we would expect the mean time to fill an order to increase with the size of the order. Do the data support this theory? Test using α = .05.
d. Find a 95% confidence interval for the mean time to fill an order consisting of 150 cases.
