My Notes

Total plasma volume is important in determining the requiredplasma component in blood replacement therapy for a personundergoing surgery. Plasma volume is influenced by the overallhealth and physical activity of an individual. Suppose that arandom sample of 45 male firefighters are tested and that they havea plasma volume sample mean of x = 37.5 ml/kg (millilitersplasma per kilogram body weight). Assume that ? = 7.20ml/kg for the distribution of blood plasma.(a) Find a 90%confidence interval for the population mean blood plasma volume inmale firefighters. What is the margin of error? (Use 2 decimalplaces.)

lower limit
upper limit
moe

(b) What conditions are necessary for your calculations? (Selectall that apply.)

? is known

the distribution of weights is normal

? is unknown

n is large

the distribution of weights is uniform

(c) Give a brief interpretation of your results in the context ofthis problem.

The probability that this interval contains the true averageblood plasma volume in male firefighters is 0.10.

10% of the intervals created using this method will contain thetrue average blood plasma volume in malefirefighters.    

90% of the intervals created using this method will contain thetrue average blood plasma volume in male firefighters.

The probability that this interval contains the true averageblood plasma volume in male firefighters is 0.90.

(d) Find the sample size necessary for a 90% confidence level withmaximal/marginal error of estimate E = 2.60 for the meanplasma volume in male firefighters.