02:06
Intro Stats / AP Statistics
Total plasma volume is important in determining the required
plasma component in blood replacement therapy for a person
undergoing surgery. Plasma volume is influenced by the overall
health and physical activity of an individual. 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 = 7.60 ml/kg for the
distribution of blood plasma.
1) 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 ?
upper limit ?
margin error ?
2) What conditions are necessary for your calculations?
Select all that apply.
the distribution of weights is normal
𝜎 is known
𝜎 is unknown
the distribution of weights is uniform
n is large
3)Interpret your results in the context of this
problem.
The probability that this interval contains the true average
blood plasma volume in male firefighters is 0.99.
The probability that this interval contains the true average
blood plasma volume in male firefighters is 0.01.
We are 99% confident that the true average blood plasma volume
in male firefighters falls within this interval.
We are 1% confident that the true average blood plasma volume in
male firefighters falls within this interval.
4)Find the sample size necessary for a 99% confidence level with
maximal margin of error E = 2.60 for
the mean plasma volume in male firefighters. Round up to the
nearest whole number.
Male firefighters ?