Question

A consumer advocacy group received a tip that an air conditioning company has been charging female customers more than male customers. The group's statistical expert decides examine this question at the α=0.10α=0.10 level of significance, by looking at the difference in mean charges between a random sample of female customers and a random sample of male customers. Let μFμF represent the average charges for female customers and μMμM represent the average charges for male customers.(Round your results to three decimal places)

Which would be correct hypotheses for this test?

• H0:μF−μM=0H0:μF-μM=0, H1:μF−μM≠0H1:μF-μM≠0
• H0:μF−μM=0H0:μF-μM=0, H1:μF−μM<0H1:μF-μM<0
• HO:μF−μM>0HO:μF-μM>0, H1:μF−μM<0H1:μF-μM<0
• H0:μF−μM=0H0:μF-μM=0, H1:μF−μM>0H1:μF-μM>0

If we are going to test this using a confidence interval, which confidence interval should we construct?

• 60%
• 80%
• 90%
• 95%

A random sample of 44 female customers were charged an average of $1231, with a standard deviation of $9. A random sample of 40 male customers were charged an average of $1207, with a standard deviation of $15. Construct the confidence interval:

  < μF−μM <

Which is the correct result:

• 0 is contained in the confidence interval, so we Reject the Null Hypothesis
• 0 is contained in the confidence interval, so we Do not Reject the Null Hypothesis
• 0 is not contained in the confidence interval, so we Do not Reject the Null Hypothesis
• 0 is not contained in the confidence interval, so we Reject the Null Hypothesis

Which would be the appropriate conclusion?

• There is not significant evidence to suggest that the company is charging its female customers more than its male customers.
• There is significant evidence to suggest that the company is charging its female customers more than its male customers.

Answer 1

Claim :- consumer advocacy group received a tip that an air conditioning company has been charging female customers more than male customers.

Hypothesis :-

H0:μF-μM=0,

H1:μF−μM>0

we are going to test this using a confidence interval, which confidence interval should we construct is 90 %

Alpha = 0.10

random sample of 44 female customers were charged an average of $1231, with a standard deviation of $9. A random sample of 40 male customers were charged an average of $1207, with a standard deviation of $15.

n1= 44, n2 = 40, xbar1 = 1231, xbar2 = 1207 , s1=9, s2 =15

90% confidence interval for two means

• Conclusion :- 0 is not contained in the confidence interval, so we Reject the Null Hypothesis
• There is significant evidence to suggest that the company is charging its female customers more than its male customers.