A building contractor has chance to purchase an odd lot of 5000 used bricks at an auction. She is interested in finding the proportion of bricks in the lot that are cracked and thus unusable for her current project, but she doesn't have sufficient time to inspect all 5000 bricks. Instead she checks 100 bricks.
a) Explain the population and sample for this problem.
b) If she found that 23 of 100 bricks were cracked, develop a 95% confidence interval for number of bricks out of 1500 that would be cracked.
c) The seller indicated that no more than 20% of her bricks are cracked. Does the buyer have reason to doubt the intergrity of the seller?