The manufacturer of the X-15 steel-belted radial truck tire claims that the mean mileage the
tire can be driven before the tread wears out is 60,000 miles. The standard deviation of
the mileage is 5,000 miles. The Crosset Truck Company bought 48 tires and found that the
mean mileage for their trucks is 59,500 miles. Is Crosset's experience different from that
claimed by the manufacturer at the .05 significance level?
Please see the attached file.
Null hypothesis:H0: µ=60,000 miles
Alternative hypothesis: Ha: µ not = 60,000 miles
We need to perform the two-tailed z test, the critical values are ...
This posting contains solution to following hypothesis testing question.