Question

The heart rate variability​ (HRV) of police officers was the subject of research published in a biology journal. HRV is defined as the variation in the time intervals between heartbeats. A measure of HRV was obtained for each in a sample of 303 police officers from the same city.​ (The lower the measure of​ HRV, the more susceptible the officer is to cardiovascular​ disease.) For the 62 officers diagnosed with​ hypertension, a 90​% confidence interval for the mean HRV was ​(6.9​,122.9​). For the 241 officers that are not​ hypertensive, a 90​% confidence interval for the mean HRV was ​(144.2​,184.9​). Use this information to complete parts a through d below. a. What confidence coefficient was used to generate the confidence intervals? (Type an integer or a decimal. Do not round) b. Give a practical interpretation of both of the 99% confidence intervals. C. When you say you are "99% confident," What do you mean? d. If you want to reduce the width of each confidence interval, should you use a smaller or larger confidence coefficient?

Answer 1

Step-by-step explanation:

Consider the provided information.

Part (A) We need to find the confidence coefficient.

The given value or percentage of probability is known as the confidence  coefficient that the interval contains the parameter.

Hence, the confidence coefficient is 0.90

Part (B) Practical interpretation of both of the 99% confidence intervals.

It means that there is 99% confident that the mean of population HRV for officers diagnosed hypertension which lies between 6.9​ and 122.9​

There is 99% confident that the mean of population HRV for officers those are not hypertensive which lies between 144.2 and 184.9.

Part (C)

If you are saying 99% confident that means the 99% of the similarly generated confidence intervals will contain the true value of the population mean in repeated sampling.

Part (D)

If We want to reduce the width of each confidence interval, you need to use smaller confidence coefficient.