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In: Statistics and Probability

A simple random sample of 3,600 persons is taken, to estimate the percentage of smokers in...

A simple random sample of 3,600 persons is taken, to estimate the percentage of smokers in a certain large population. It turns out that 1,217 people in the sample are smokers.

(a) Find the estimated percentage of smokers in the population.

(b) Find the standard error of the estimated percentage of smokers in (a).

(c) Find a 95% confidence interval of the percentage of smokers in the population.

(d) Find the margin of error for your estimation of the percentage of smokers.

(e) Find the estimated variance and standard deviation of the estimated percentage of smokers

2. A survey is to be conducted to study work absence due to acute illness in factory with 1200 workers. Suppose the mean number of days lost per year is 4.6 and that the standard deviation is 2.7 days lost per year, and the sample is to be selected by simple random sampling. What sample size is needed to produce an estimate of the mean number of days lost with a standard error of se(y) = 0.15?

Solutions

Expert Solution

1)

Given : n=3600 , x=1217

(a) The estimated percentage of smokers in the population is ,

(b) The standard error of the estimated percentage of smokers is ,

(c) The 95% confidence interval of the percentage of smokers in the population is ,

(d) The margin of error for your estimation of the percentage of smokers is ,

(e) The estimated variance and standard deviation of the estimated percentage of smokers is ,

Standard deviation = S. E. = 0.0079

orchestra answered 2 years ago
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