Posted by **Megan** on Sunday, May 5, 2013 at 5:51pm.

A doctor wants to estimate the HDL cholesterol of all 20-29 year old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99%confidence assuming s=17.8 based on earlier studies? Suppose the doctor would be content with 90% confidence. How does the decrease in cofidence affect the sample size required?

A: A 99% confidence level requires ___ subjects

B: A 90% confidence level requires ___ subjects

- 7 STATS MATHGURU PLEASE HELP -
**MathGuru**, Sunday, May 5, 2013 at 6:07pm
2.58 = 99% confidence interval

1.645 = 90% confidence interval

Use a formula to find sample size.

Here is one:

n = [(z-value * sd)/E]^2

...where n = sample size, z-value = values above for the intervals needed, sd = 17.8, E = .02, ^2 means squared, and * means to multiply.

Plug the values into the formula and finish the calculations. Round your answers to the next highest whole number.

I'll let you take it from here.

## Answer this Question

## Related Questions

- Statistics 7 - A doctor wants to estimate the HDL cholesterol of all 20 to 29 ...
- Statistics - A doctor want to estimate the HDL cholesterol of all 20- to 29- ...
- statistics - Suppose that in the aerobic exercise group we also measured the ...
- biostatistics - 7. Consider again the data in problem #6. Suppose that in the ...
- college biology - Why LDL is considered the bad cholesterol and HDL the good ...
- Computers - Create a class named Checkup with fields that hold a patient number...
- statistics - In a test of the effectiveness of garlic for lowering cholesterol, ...
- INTERVAL OF THE MEAN - In a test of of garlic for lowering cholesterol, 45 ...
- biostatistics - A studyis run to estimate the mean total cholesterol level in ...
- Stats - A researcher wants to estimate the mean serum cholesterol level for ...

More Related Questions