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 660.
A random sample of n=22 Canadians between the ages of 25 to 40 was taken, the mean was found to be 663, with a standard deviation of 25.2.
(a) Choose the correct statistical hypotheses.
A. H0:X―≥660,HA:X―<660
B. H0:μ>660,HA:μ<660
C. H0:μ≥660HA:μ<660
D. H0:μ=660,HA:μ≠660
E. H0:X―>660,HA:X―≤660
F. H0:X―=660,HA:X―≠660
(b) Find a 93% confidence interval for μ. Use at least 4 digits after the decmial if rounding.
Minimum lower bound = _when α=7%
Maximum upper bound = _ when α=7%
(c) The sampling distribution used to calculate the confidence interval in part (b) follows any Student's T distribution OR a Standard Normal distribution OR a Student's T distribution with degrees of freedom 21 OR a Student's T distribution with degrees of freedom 22 OR a Bootstrapped distribution.
(d) Conducting your statistical test at α=7%, you should reject OR not reject the null hypothesis.
One can conclude from this sample that the credit score OR the mean credit score is less than 660 OR not less 660 OR not the same as 660 OR similar to 660.