One critical factor that determines the success of a catalogue store chain is the availability of
products that consumers want to buy. If a store is sold out, future sales to that customer are
less likely. Accordingly, delivery trucks operating from a central warehouse regularly resupply
stores. In an analysis of a chain’s operations, the general manager wanted to determine the
factors that are related to how long it takes to unload delivery trucks. A random sample of 50
deliveries to one store was observed.
File name: Catalogue.xls Variables:
The times (in minutes) to unload the weight (in hundreds of pounds) of the boxes were
Determine the multiple regression equation.
Question 1: What are the hypothesis statements of this study?
Question 2: Analyse and explain the correlations between the variables of the study. Is there
a relationship between the times, unload the weight and boxes were recorded?
Question 3: Explain the fits of regression models. Is the model valid?
Question 4: Interpret and test the coefficients.
a. Produce a 95% interval of the amount of time needed to unload a truck with 100 boxes
weighing 5,000 pounds.
b. Produce a 95% interval of the average amount of time needed to unload trucks with
100 boxes weighing 5,000 pounds.