Answer:
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
Data given
represent the sample mean for men
represent the sample mean for women
represent the sample deviation for men
represent the sample deviation for women
sample size of male
sample size of women
The confidence interval is given by:
(1)
The polled variance can be calculated with this formula:
For a confidence of 95% the value for the significance is and , the degrees of freedom are given by:
And the critical value can be calculated with the following formula in excel: "=T.INV(1-0.025,18)" and we got
Now we can replace into the confidence interval: