Joan's Nursery specializes in custom-designed landscaping for residential areas. The estimated labor cost associated with a particular landscaping proposal is based on the number of plantings of trees, shrubs, and so on to be used for the project. For cost-estimating purposes, managers use two hours of labor time for the planting of a medium-sized tree. Actual times from a sample of 10 plantings during the past month follow (times in hours). 1.6 1.6 2.5 2.3 2 . 3 2.3 2.6 3.0 1.5 2.3 With a 0.05 level of significance, test to see whether the mean tree-planting time differs from two hours. (a) State the null and alternative hypotheses. OHO: HS 2 Ha : H > 2 OHO: H 2 Ha: US 2 O' Ho: H = 2 Ha: H # 2 OHO: H 2 2 Him