Question

H. continued The average credit card debt for a recent year was $9205. Five years earlier the average credit card debt was $6618. Assume sample sizes of 35 were used and the population standard deviations of both samples was $1928. At a 0.05 level of significance test the claim that the recent credit card debt is greater than it was 5 years ago. 2.

Answer 1

Hypothesis:
H0 : mu = 6618
Ha : mu > 6618

Test statistics:

z = ( x -mean) /(s/sqrt(n))
= ( 9205 - 6618)/(1928/sqrt(35))
= 7.94

P value = 0.00001.

we reject the null hypothesis