Question

In 2010, the mean for the number of pets owned per household was 1.9. A poll of 1023 households conducted this year reported the mean for the number of pets owned per household to be 1.8. Assuming sigma = 1.1, is there sufficient evidence to support the claim that the mean number of pets owned has changed since 2010 at the alpha = 0.1 level of significance?

Answer 1

Solution :

= 1.9

= 1.8

= 1.1

n = 1023

This is the two tailed test .

The null and alternative hypothesis is

H₀ :   = 1.9

H_a : 1.9

Test statistic = z

= ( - ) / / n

= (1.8 - 1.9) /1.1 / 1023

= -2.908

P (Z < -2.908) =0.0036

P-value = 0.0036

= 0.10

p=0.0036<0.1

Reject the null hypothesis .

There is sufficient evidence to suggest that