Question
The monthly incomes from a random sample of workers in a factory are shown
below.
Monthly Income
(In $1,000)
4.0
5.0
7.0
4.0
6.0
6.0
7.0
9.0
a. Compute the standard error of the mean (in dollars).
b. Compute the margin of error (in dollars) at 95% confidence.
c. Compute a 95% confidence interval for the mean of the population.
Assume the population has a normal distribution. Give your answer in dollars.
below.
Monthly Income
(In $1,000)
4.0
5.0
7.0
4.0
6.0
6.0
7.0
9.0
a. Compute the standard error of the mean (in dollars).
b. Compute the margin of error (in dollars) at 95% confidence.
c. Compute a 95% confidence interval for the mean of the population.
Assume the population has a normal distribution. Give your answer in dollars.
Answers
MathGuru
You will need to compute the mean and standard deviation. Once you have those values, you can compute the rest using formulas.
a) standard error of the mean = sd/√n
Note: sd = standard deviation; n = sample size
b) Margin of error = 1.96(sd/√n)
Note: 1.96 represents 95% using a z-table
c) CI95 = mean ± 1.96(sd/√n)
I'll let you take it from here.
a) standard error of the mean = sd/√n
Note: sd = standard deviation; n = sample size
b) Margin of error = 1.96(sd/√n)
Note: 1.96 represents 95% using a z-table
c) CI95 = mean ± 1.96(sd/√n)
I'll let you take it from here.