Question

A magazine claims the mean monthly cost of video games in $30. You Sample 25 houses and find a mean of $25.7 and a standard deviation of $5.12. At α=.1, do you have enough evidence to reject the claim

Answer 1

Solution :

= 30

= 25.7

s = 5.12

n = 25

This is the two tailed test .

The null and alternative hypothesis is ,

H₀ :   = 30

H_a :     30

Test statistic = t

= ( - ) / s / n

= (25.7 - 30) /5.12 / 25

= - 4.199

P(z < - 4.199 ) = 0.0003

P-value = 0.0003

= 0.01  

p = 0.0003 < 0.01, it is concluded that the null hypothesis is rejected.

Reject the null hypothesis .

There is enough evidence to claim that the population mean μ is different than 30, at the 0.01 significance level .