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.
Radiation in Baby Teeth Listed below are amounts of strontium-90 (in millibecquerels or mBq per gram of calcium) in a simple random sample of baby teeth obtained from Pennsylvania residents and New York residents born after 1979 (based on data from "An Unexpected Rise in Strontium-90 in U.S. Deciduous Teeth in the 1990s," by Mangano, et al., Science of the Total Environment).
a. Use a 0.05 significance level to test the claim that the mean amount of strontium-90 from Pennsylvania residents is greater than the mean amount from New York residents.
b. Construct a 90% confidence interval of the difference between the mean amount of strontium-90 from Pennsylvania residents and the mean amount from New York residents
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Pennsylvania:
|
155
|
142
|
149
|
130
|
151
|
163
|
151
|
142
|
156
|
133
|
138
|
161
|
|
New York:
|
133
|
140
|
142
|
131
|
134
|
129
|
128
|
140
|
140
|
140
|
137
|
143
|