Question

can you help me

Answer 1

You have data from a sample of 80 workers at a local factory who are full time employees. The mean systolic blood pressure of this sample 130. You know that the population standard deviation (σ) of all workers' systolic blood pressure at the local factory is 15.



Which of the below represents a 95% confidence interval for the unknown population mean systolic blood pressure of local factory workers who are full time employees.

(hint: since the population standard deviation (σ) is known, you can use the z-distribution for your confidence interval construction.)

The correct answer is A. [126.71 – 133.29]

Answer 2

Use data from the previous question: "You have data from a sample of 80 workers at a local factory who are full time employees. The mean systolic blood pressure of this sample 130. You know that the population standard deviation (σ) of all workers' systolic blood pressure at the local factory is 15."

Which of the below represents the best interpretation of the 95% confidence interval you calculated on the previous question for the unknown population mean systolic blood pressure of local factory workers who are full time employees?

*note: the actual values for the confidence interval limits are left blank intentionally

Select one:
A. About 95% of local factory workers who are full time employees have a systolic blood pressure between ___ and ___.
B. We are 95% confident that the unknown population mean systolic blood pressure of local factory workers who are full time employees falls between ___ and ___.
C. It is guaranteed that the unknown population mean systolic blood pressure of local factory workers who are full time employees falls between ___ and ___.
D. We are 95% confident that the sample mean systolic blood pressure of local factory workers who are full time employees falls between ___ and ___.

Answer 3

@kropot72 Could you help us solve this?

Answer 4

I hope that the following definition will help you to make the correct choice of answer:

'A 95% confidence interval for the population mean is an interval such that on average, 95 out of every 100 such intervals will contain the population mean.'

Answer 5

So is it B then

Answer 6

Yes, B is the correct choice.