Question

USE EXCEL TO SOLVE

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):

1.7 1.5 2.4 2.2 1.9 2.3 2.1 1.6 1.4 2.3

At the 10% significance level test using p-value method to see whether the mean tree-planting time is less than two hours?

Answer 1

	Values ( X )
	1.7	0.0576
	1.5	0.1936
	2.4	0.2116
	2.2	0.0676
	1.9	0.0016
	2.3	0.1296
	2.1	0.0256
	1.6	0.1156
	1.4	0.2916
	2.3	0.1296
Total	19.4	1.224

To Test :-

H0 :-

H1 :-

Test   Statistic :-                               
                   

t = -0.5145                              

P value

Looking for value | t | = 0.5415 in t table across 9 degree of freedom

| t | = 0.5415   lies between the values 0.000 and 0.703 with respective P values are 0.50 and 0.25

Using excel to calculate exact P value = 0.3097

Reject null hypothesis if P value < level of significance

0.3097 > 0.10, we fail to reject null hypothesis

Conclusion :- Accept Null Hypothesis

There is no sufficient evidence to support the claim that the mean tree-planting time is less than two hours.