Question 962979
Suppose that a random sample of 40 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that σ = 7.00 ml/kg for the distribution of blood plasma. 
(a) Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.) 
lower limit?:: x-bar - inv(Norm0.995)s/sqrt(n) = 37.5-2.5758*(7/sqrt(40)) 
upper limit?:: 37.5+2.5758*(7/sqrt(40))
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margin of error? 2.5758*(7/sqrt(40))
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 (d) Find the sample size necessary for a 99% confidence level with maximal error of estimate E = 2.60 for the mean plasma volume in male firefighters. (Round up to the nearest whole number.)
n = [2.5758*7/2.6]^2 = 49 when rounded up
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 49 male firefighters 
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Cheers,
Stan H.
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