In Exercises 5-20, assume that the two samples are independent simple random samples selected from
- a. Test the given claim using the P-value method or critical value method.
- b. Construct a confidence interval suitable for testing the given claim.
20. 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, Vol. 317). Use a 0.05 significance level to test the claim that the
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Essentials of Statistics, Books a la Carte Edition (5th Edition)
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- A highway safety researcher is studying the design of a freeway sign and is interested in the mean maximum distance at which drivers are able to read the sign. The maximum distances (in feet) at which a random sample of 16 drivers can read the sign are as follows: 460 550 660 600 600 660 300 500 420 660 250 460 550 600 500 550 The mean of the sample of 16 distances is 520 feet with a standard deviation of 121 feet. (a) What assumption must you make before constructing a confidence interval? 1) The population distribution is Uniform. 2) The population distribution is Normal. (b) At the 90% confidence level what is the margin of error on your estimate of the true mean maximum distance at which drivers can read the sign. Answer=_________ feet (round to the nearest whole number) (c) Construct a 90% confidence interval estimate of the true mean maximum distance at which drivers can read the sign. Lower value=_______ feet (round to the nearest whole number) Upper value=…arrow_forwardWhat is the minimum sample size necessary to construct a 90% confidence interval for with a margin of error E = 0.1? assume that the population standard deviation is = 0.9.arrow_forwardGiven that the population standard deviation is 5.6, determine the minimum sample size needed in order to estimate the population mean so that the margin or error is at most E = 0.5 at the 90% confidence level.arrow_forward
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