The average credit card debt for a recent year was $8,776. Five years earlier the average credit card debt was $8,189. Assume sample sizes of 32 were used and the population standard deviations of both samples were $690. Is there evidence to cónclude that the average credit card debt has increased? Use a- 0.05 a. State the hypotheses
b. Find the critical value.
c. Compute the test statistic
d. Make the decision.
e. Summarize the results

We reject H₀.  We support that the new average credit card debt is bigger than the previous average

Step-by-step explanation:

Five years earlier

μ   = 8189

σ  =  690

Sample size   n  = 32

Recent year debt

x  =  8776

Sample size   n  = 32

a) Hypothesis Test:

Null Hypothesis                        H₀            x  =  μ   = 8189

Alternative Hypothesis           Hₐ             x >  μ

b) z(c)  Alternative Hypothesis establishes that the test is a one tail-test to the right.

z(c)   for significance level  α = 0.05    is  from z-table      z(c) = 1,64

c) z(s)  =  (  x  -   μ ) / σ /√n

z(s)  =  ( 8776  - 8189 ) / 690 /√32

z(s)  =  587 *5,66/ 690

z(s) = 4,81

d) Comparing   z(c)    and z(s)

z(s)  >  z(c)   Then z(c) is in the rejection region and we reject H₀

e) We have evidence that at 95 % of confidence the new value for the debt in credit card is now bigger than the average

sorry not sure

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.