Question 959200
The Highway Safety Institute conducted test crashes at 6 mph, calculating the costs for the damage caused. The costs for the five test crashes were $7480, $4910, $9050, $6375, and $4275. Use these data to test the claim that the mean cost of a 6mph crash is different from $5000. Use a 5% level of significance.
---------------------------
 A) state the null and alternative hypothesis
Ho: u = 5000
Ha: u # 5000 (claim)
----------------------- 
B) identify the critical value(s),
Since n < 30 use a t value::
t =  +/- 2.7765
---- 
C) calculate the test statistic,
mean of the sample = 6418 ; s = 1931.55
t(6418) = (6418-5000)/[1931.55/sqrt(5)] = 1.6415
------ 
D) make a decision to reject the null hypothesis or not, and
Because the test stat is not in the reject interval, fail to 
reject Ho at the 5% level of significance.
----------------------- 
E) state a full conclusion in the context of the problem.
The test results do not support the claim that u is different
than 5000.
Cheers,
Stan H.