Give an estimate of the sample size needed to obtain the specified
margin of error for a 95% confidence interval;

Margin or error = 0.01, standard deviation = 0.25

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Researchers want to determine the mean number of hours students spend
watching TV. A margin of error of 0.25 hour is desired. Past studies
suggest a population standard deviation of 1.7 hours is reasonable.
Estimate the minimum sample size required to estimate the population
mean.

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Based on a sample of 62 homes, the data offered gives the mean weight
in pounds and the standard deviation for paper, glass & plastic. For
each catagory estimate the mean weight for the entire population of
homes. Give the 95% confidence interval.

                Sample Mean                       Sample Standard Deviation
Paper           9.42                              4.12
Glass           3.75                              3.11
Plastic         1.91                              1.07