Look back at the prices for the external disk drives we saw in Exercise 10.

The least squares line is Price = 15.112 + 62.417 Capacity.

The assumptions and conditions for regression are met.

SE1b12 = 11.328

a) Disk drives keep growing in capacity. Some tech experts now talk about Petabyte 1PB = 1000 TB = 1,000,000 GB2 drives. What does this model predict that a Petabytecapacity drive will cost?

b) Find a 95% prediction interval for the price of a 1 PB drive.

c) Are these predictions likely to be useful? Explain.