Refer to the previous exercise, which gives data on truss heights for a sample of warehouses and the corresponding sale prices.
a. Estimate the true average change in sale price associated with a one-foot increase in truss height, and do so in a way that conveys information about the precision of estimation.
b. Estimate the true average sale price for all warehouses having a truss height of 25 ft, and do so in a way that conveys information about the precision of estimation.
c. Predict the sale price for a single warehouse whose truss height is 25 ft, and do so in a way that conveys information about the precision of prediction. How does this prediction compare to the estimate of (b)?
d. Without calculating any intervals, how would the width of a 95% prediction interval for sale price when truss height is 25 ft compare to the width of a 95% interval when height is 30 ft? Explain your reasoning.
e. Calculate and interpret the sample correlation coefficient.