A recent study reported that the average credit score for a new-car loan was 753
ID: 3289452 • Letter: A
Question
A recent study reported that the average credit score for a new-car loan was 753.Suppose Ally Financial, a bank holding company that finances car loans, would like test the hypothesis that the average credit score has increased since the study. A random sample of 20 new-car loans had an average credit score of 764.2 with a sample standard deviation of 34.5. Ally Financial would like to set alpha = 0.05. What is the test statistic for this hypothesis test? A. z_x = 2.04 B. t_x = 2.31 C. t_x = 1.45 D. z_x = 1.25Explanation / Answer
test statstic
here n=20, x=764.2 s=34.5 mu=753
t=x-mu/(s/sqrt(n))
=764.2-753/(34.5/sqrt(20))
t=1.4518238
answer is option C