A trucking firm spspects that the mean like of a certain tire it uses is less than 34,000 miles. To check the claim, the firm randomly selects and tests 18 of these tires and gets a mean lifetime of 33,350 miles with a standard deviation of 1200 miles. At a 0.05 level of significance, test the trucking firm's claim.

My answer is:

Claim: mean < 34,000
Ho: mean < 34,000
Ha: mean >_ 34,000
Claim is a mean
Test used: Z-test
P- value .993
p=.993 > 0.05
Fail to reject Ho