Using the multiple linear model that assumes Unloading time is a function of of Volume, Weight and Shift, estimate the 95% C.I. for the mean unloading time of a shipment that has a volume of , weights 60 000 kg and arrived during the Day shift. Hint: The following command could be useful New.X = data.frame(Volume=70, Weight=60, Shift="Day")

Supermkt Volume Weight Shift Unload 79 43 Day 48 76 46 Day 42 84 43 Day 44 66 32 Day 33 98 56 Day 53 98 57 Day 58 92 56 Day 52 73 38 Day 34 80 44 Day 40 62 37 Day 24 87 45 Night 47 67 32 44 Night 37 Night 62 30 76 36 Night 39 93 55 Night 56 61 41 Night 23 53 32 Night 20 63 43 Night 35 77 49 Night 42 59 40 Night 19