An automobile club claims that the average time for a nonsto

An automobile club claims that the average time for a non-stop trip from New York City to Washington, D.C by automobile in 4.5 hours. A disbelieving driver feels that the claims is incorrect. The driver randomly questions 49 people who recently made the trip and finds that aver non-stop time was4.4 hours with a sample standard deviation of 0.35 hours.

Run the appropriate statistical test to determine if there is a statistically significant difference between the automobile club claim and the disbelieving driver\'s sample test result ( use 5% )

Solution

H0 : POPULATION MEAN = 4.5 AGAINST POPULATION MEAN NOT EQUALS 4.5...
Sample mean = 4.4 and sample s.d = 0.35 and sample size = 49..
so, sample standard error = ( 0.35 / sqrt(49) ) = 0.05..

Test statistic = ( 4.4 - 4.5 ) / 0.05 = -2

with d.f = 49-1 = 48..

p-value =  0.05117593...which is more than 0.05..so, we accept H0 and state that the driver is incorrect and the average time is indeed equal to 4.5 hours!