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 plantings of trees,shrubs and so on to be used for the project. for cost-estimated purposes, managers use two hours of labour time for the planting of a medium sized tree. actual times from a sample of ten plantings 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

with a 0.05 level of significance, test to see whether the mean tree-planting time differs from two hours.

1) state the null and alternative hypothesis

2) compute the sample mean

3) compute the sample standard deviation

4) compute the sample (test) statistic

5) formulate the decision rule

6) what is your conclusion