Question

A statewide real estate sales agency, Farm Associates, has records indicate that
the mean selling time of farm property in Texas is 80 days. Because of
recent drought conditions, the agency believes that the mean selling time is
now greater than 80 days.

A survey of 100 farms sold recently revealed that the mean selling time is 82
days, with a standard deviation of 18 days.

At 0.05 significance level, has there been an increase in selling time?

Answer 1

Given    =80 days

= 82 days

n= 100

standard deviation = 18 days

H0: =80

H1: > 80 that is there is  an increase in selling time ( one tailed or right tailed alternative)

significance level =0.05

Test statistics   

  

Test statistics Z =1.111

Critical value of Z 0.05 for right tail  = 1.645

p value =0.1335

Decision: Test statistics Z(1.111) < 1.645

   or    p value(0.1335) > 0.05

Fail to reject H0

Conclusion: We conclude that here is no increase in mean selling time