Credit scores are used by banks, financial institutions, and retailers to determine one's trustworthiness, and their ability to pay their credit card, when he/she is given a credit card. The higher the credit score, the better the credit (and the more financially trustworthy) a consumer is. In light of the current economic downturn, an economist claims that the credit score of Canadians between the ages of 25 to 40 has remained the same. Prior to the current economic downturn, the mean credit score for Canadians between the ages of 25 to 40 was 698. A random sample of n=20 Canadians between the ages of 25 to 40 was taken, the mean was found to be 701, with a standard deviation of 50. (a) Choose the correct statistical hypotheses. A. H0:=698,HA:698 B. H0:X=698,HA:X698 C. H0:X>698,HA:X698 D. H0:>698,HA:<698 E. H0:698HA:<698 F. H0:X698,HA:X<698 (b) Find a 93% confidence interval for . Use at least 4 digits after the decmial if rounding.

Minimum lower bound =

when =7%

Maximum upper bound =

when =7% (c) The sampling distribution used to calculate the confidence interval in part (b) follows ? any Student's T distribution a Standard Normal distribution a Student's T distribution with degrees of freedom 19 a Student's T distribution with degrees of freedom 20 a Bootstrapped distribution . (d) Conducting your statistical test at =7%, you should ? reject not reject the null hypothesis. One can conclude from this sample that ? the credit score the mean credit score is ? less than 698 not less 698 not the same as 698 similar to 698 .