Question 325017: Use the following to answer questions 14-17:
A study by a bank compared the average savings of customers who were depositors for three years or less, with those who had been depositors for more than three years. The results of a sample are:
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- 3 years > 3 years
Mean savings balance $1200 $1250
Standard deviation $100 $150
Sample size 10 15
14. Assuming that the financial officer wants to show that there is a difference in the average savings balance between the two classes of depositors, what is the null hypothesis? _____________________
15. For = 0.05, what is the critical value of t? ___________
16. What is the computed test statistic? ______________
17. What is the p-value if = .05 and the test statistic is 2.807? _____
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A study by a bank compared the average savings of customers who were depositors for three years or less, with those who had been depositors for more than three years. The results of a sample are:
<
- 3 years > 3 years
Mean savings balance $1200 $1250
Standard deviation $100 $150
Sample size 10 15
14. Assuming that the financial officer wants to show that there is a difference in the average savings balance between the two classes of depositors, what is the null hypothesis? _____________________
Ho: u(<3)-u(>3) = 0
Ha: u(<3)-u(>3) is not 0
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15. For alpha = 0.05, what is the critical value of t?
Using df = n1-1 + n2-1 = 23 I get +-invT(0.975,23) = +- 2.0687_____
16. What is the computed test statistic? t = -1_____
Using a TI-84 I get t = -1 on a 2-SampleZtest.
17. What is the p-value if alpha = .05 and the test statistic is 2.807?
p-value = 2*P(t > 2.80 when df=23) = 2*tcdf(2.80,100,23) = 0.0102
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Cheers,
Stan H.
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