Question

Find a 95% confidence interval for the mean(mew)of the population.

Use the value of s you calculated as a substitute for the value of StDev required in the confidence interval calculation

Mean(Mew) - 69. 37

s (sample stdev) - 3.24

A) What is the margin of error in your confidence interval?

B) Explain what this confidence interval means.

Answer 1

we know that the confidence interval is given as

mean +- z*sd/sqrt(n)

from the z table , we see than for 95% CI the value of z is 1.96

so

mean +- z*sd/sqrt(n)

mean = 69.37
sd = 3.24

69.37 +- 1.96*3.24/sqrt(n)

here n is not given but we can put the values in n and solve for upper and lower limit

margin of error is given as

MOE = z*sd/sqrt(n)
= 1.96*3.24/sqrt(n)

Interpretation

when we calculate the upper and lower limit of the confidence interval , we say that we are 95% confident that the true value of the mean lies in the interval given by

Lower limit , upper limit