A study found that the average stopping distance of a school bus traveling 50 miles per hour was 264 feet. A group of automotive engineers decided to conduct a study of its school buses and found that, for 20 buses, the average stopping distance of buses traveling 50 miles per hour was 262.3 feet. The standard deviation was 3 feet. To test the claim that the average stopping distance of the company’s buses is actually less than 264 feet,
State the hypotheses, Calculate the Test Statistic, find the P-Value, and make the decision whether to reject Ho or not, using α= 0.05.
H0: = 264
Ha: < 264
Test Statistic :-
t = ( X̅ - µ ) / (S / √(n) )
t = ( 262.3 - 264 ) / ( 3 / √(20) )
t = -2.53
From T table,
With test statistics of 2.53 and df of 19,
p-value = 0.0102
Since p-value < 0.05, Reject H0
We conclude that we have sufficient evidence to support the claim that the average stopping
distance of the company’s buses is actually less than 264 feet.
Get Answers For Free
Most questions answered within 1 hours.