Question

1. Ten years ago, a large nursery sold hundreds of trees to the city through the Department of Parks and Recreation with the pledge that in ten years, they would reach a minimum mean height of 5.5 feet with a standard deviation od 9 inches. This week the city manager randomly selected 81 trees and found the mean height to be 5 feet. Would the sample result support a city request for a partial refund from the nursery for breach of contract because the average height is less than 5 feet? Test at the 1% significance level.

Answer 1