Question

Here is an example you can use: the mean of a random sample is 15 and the margin of error figured for the 95% confidence interval is 3.5

1. What does the margin of error imply?

2. Estimate population mean using given information above. Interpret your interval estimate for population mean.

Answer 1

Solution:

Given ,

sample mean = 15

Margin of error = 3.5

confidence level = c = 95%

1.

We are 95% confident that the population mean is within 3.5 of the 15.

2.

Confidence interval for mean is given by

sample mean margin of error

15 3.5

(15 - 3.5 , 15 + 3.5)

(11.5 , 18.5)

The 95% confidence interval for the population mean is (11.5 , 18.5)