Assignment:
Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal, unless your instructor stipulates otherwise.
BMI for Miss America The trend of thinner Miss America winners has generated charges that the contest encourages unhealthy diet habits among young women. Listed below are body mass indexes (BMI) for Miss America winners from two different time periods. Consider the listed values to be simple random samples selected from larger populations.
a. Use a 0.05 significance level to test the claim that recent winners have a lower mean BMI than winners from the 1920s and 1930s.
b. Construct a 90% confidence interval for the difference between the mean BMI of recent winners and the mean BMI of winners from the 1920s and 1930s.
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BMI (from recent winners):
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19.5
|
20.3
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19.6
|
20.2
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17.8
|
17.9
|
19.1
|
18.8
|
17.6
|
16.8
|
|
BMI (from the 1920s and 1930s):
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20.4
|
21.9
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22.1
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22.3
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20.3
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18.8
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18.9
|
19.4
|
18.4
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19.1
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