The credit manager for Braxton\'s department store, in examining account for var

Question

The credit manager for Braxton's department store, in examining account for various types of customers served by the establishment, has noticed that the mean outstanding balance for a sample of 20 customers from the local ZIP code is $375, with a standard deviation of $75. For a sample of 25 customers from a nearby ZIP code, the mean and standard deviation was $425 and $143, respectively. Assuming normal populations and sing the 0.05 level of significance, examine whether credit customers from the two ZIP codes might have the same mean outstanding balance. What is the most accurate statement that could be made about the p-value for this test? Construct and interpret the 95% confidence interval for the difference between the population means. Is the hypothesized difference (0.00) within the interval? Given the presence or absence of the 0.00 value within the interval, is this consistent with the findings of the hypothesis test?

Explanation / Answer

mean1 eq: 375 (variance= 5625) (se= 16.7705)
mean2 eq: 425 (variance= 20449) (se= 28.6)

Probability that var1<var2
p=0.99716 (left: 0.0028; double: 0.0056)

Difference between means:
-M2=375-425=-50
sd=203.6; se=33.154
95% CI of difference:
-114.9814 <-50< 14.981 (Wald)
t-difference: -1.508
df-t: 37.2; p= 0.06917
(left p: 0.9308; two sided: 0.1384)

It cannot be conclusively stated that the two means are different.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.