Joan’s Nursery specializes in custom-designed landscaping for residential areas. The estimated labour cost associated with a particular landscaping proposal is based on the number of planting of trees, shrubs, and so on to be used for the project. For cost-estimating purposes, managers use two hours of labour time for the planting of a medium-sized tree. Actual times from a sample of 10 planting during the past month follow (times in hours). 1.7 1.5 2.6 2.2 2.4 2.3 2.6 3.0 1.4 2.3
Test to see whether the mean tree-planting time differs from two hours.
State the null and alternative hypothesis