Joan's Nursery specializes in custom-designed landscaping forresidential areas. The estimated labor cost associated with aparticular landscaping proposal is based on the number of plantingsof trees, shrubs, and so on to be used for the project. Forcost-estimating purposes, managers use two hours of labor time forthe planting of a medium-sized tree. Actual times from a sample of10 plantings during the past month follow (times in hours).

1.8

1.4

2.7

2.1

2.4

2.3

2.6

3.0

1.4

2.3

With a 0.05 level of significance, test to see whether the meantree-planting time differs from two hours.

(a)State the null and alternative hypotheses.

a)H₀: ? ? 2

H_a: ? > 2

b)H₀: ? < 2

H_a: ? ? 2

c)H₀: ? = 2

H_a: ? ? 2

d)H₀: ? ? 2

H_a: ? < 2

e)H₀: ? > 2

H_a: ? ? 2

(b)Compute the sample mean.

(c)Compute the sample standard deviation. (Round your answer tothree decimal places.)

(d)What is the test statistic? (Round your answer to threedecimal places.)

test statistic=

What is the p-value? (Round your answer to four decimalplaces.)

p-value =

(e)What is your conclusion?

Do not reject H₀. We can conclude that themean tree-planting time differs from two hours. There is a reasonto change from the two hours for cost estimating purposes.

Reject H₀. We cannot conclude that the meantree-planting time differs from two hours. There is no reason tochange from the two hours for cost estimatingpurposes.    

Do not reject H₀. We cannot conclude thatthe mean tree-planting time differs from two hours. There is noreason to change from the two hours for cost estimatingpurposes.

Reject H₀. We can conclude that the meantree-planting time differs from two hours. There is a reason tochange from the two hours for cost estimating purposes.