In: Statistics and Probability
verproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma.† Over a period of months, an adult male patient has taken ten blood tests for uric acid. The mean concentration was x = 5.35 mg/dl. The distribution of uric acid in healthy adult males can be assumed to be normal, with σ = 1.83 mg/dl.(a) Find a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. What is the margin of error? (Round your answers to two decimal places.)
lower limit | |
upper limit | |
margin of error |
(b) What conditions are necessary for your calculations? (Select
all that apply.)
normal distribution of uric acidσ is unknownσ is knownuniform distribution of uric acidn is large
(c) Interpret your results in the context of this problem.
There is not enough information to make an interpretation.The probability that this interval contains the true average uric acid level for this patient is 0.05. There is a 95% chance that the confidence interval is one of the intervals containing the population average uric acid level for this patient.The probability that this interval contains the true average uric acid level for this patient is 0.95.There is a 5% chance that the confidence interval is one of the intervals containing the population average uric acid level for this patient.
(d) Find the sample size necessary for a 95% confidence level with
maximal margin of error E = 1.08 for the mean
concentration of uric acid in this patient's blood. (Round your
answer up to the nearest whole number.)
blood tests
n=10, = 5.35, σ = 1.83, c= 95%
a)
formula for margin of error is
Where Zc is the z critical value for c=95%
Zc= 1.96
= 1.1342458
margin of error= 1.13
5.35 - 1.13 < < 5.35 + 1.13
4.22 < < 6.48
lower limit = 4.22
upper limit = 6.48
margin of error=
1.13
b)
normal distribution of uric acid
σ is known
c)
There is a 95% chance that the confidence interval is one of the intervals containing the population average uric acid level for this patient.
d)
E=1.08, c=95%, σ = 1.83
formula for sample size is
Zc= 1.96
n= 11.029779
n= 12
sample size necessary = 12