An important problem in industry is shipment damage. A electronics distribution company ships its product by truck and determines that it cannot meet its profit expectations if, on average, the number of damaged items per truckload is greater than 12. A random sample of 12 departing truckloads is selected at the delivery point and the average number of damaged items per truckload is calculated to be 9.4 with a calculated sample of variance of 0.64. Select a 99% confidence interval for the true mean of damaged items. a) [48.26, -30.02]
b) [10.67, 11.93]
c) [-0.6285, 0.6285]
d) [10.69, 11.91]
e) [11.37, 12.63]
f) none of the above