Answer:
Claim cannot be rejected
Step-by-step explanation:
We solve this by using hypothesis testing
H0: mean = 40
H1: mean ≠ 40
We have samples of 30, but we were not gives the population standard deviation. We used the t distribution
T score = 39.2-40/(7.5/√30)
= -0.5842
Degree of freedom = 30-1 = 29
Then p value = 0.5636
In conclusion, we fail to reject the null hypothesis since 0.5636 > 0.01 significance level.
So company's claim cannot be rejected