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 useone and a halfhours of labor time for the planting of a medium-sized tree. Actual times from a sample of10plantings during the past month follow (times in hours).

2.4, 2.8, 2.7,1.5 1.8, 2.3, 2.7, 0.9, 1.1, 3.0

With a0.05level of significance, test to see whether the mean tree-planting time differs fromone and halfhours.

a.State the null and alternative hypotheses.

Ha: u ____ 1.5

Ho: u ____ 1.5

b.Compute the sample mean.

(to 1 decimal)

c.Compute the sample standard deviation.

(to 3 decimals)

d.What is thep-value?

-value(to 3 decimals)-value

- Select your answer -

lower than .005

between .005 and .0125

between .0125 and .025

between .025 and .05

between .05 and .10

greater than .10

Item 6

e.What is your conclusion?

We- Select your answer -

do not

do

Item 7

reject the null. There- Select your answer -

is not

is

Item 8

enough evidence to prove that the mean tree-planting time differs fromhours.