Posted by **Tom** on Saturday, March 13, 2010 at 8:46pm.

A statistics practitioner would like to estimate a population mean to within 50 units with 99% confidence given that the population standard deviation is 250.

a) What sample size should be used.

b) Repeat part (a) with a standard deviation of 50.

c) Repeat part (a) using a 95% confidence level.

d) Repeat part (a) when we wish to estimate the population mean to within 10 units.

- statistics -
**MathGuru**, Monday, March 15, 2010 at 7:12pm
Formula:

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

...where n = sample size, use a z-table to represent the 99% confidence interval, sd = 250, E = 50, ^2 means squared, and * means to multiply.

Plug the values into the formula and finish the calculation. Round your answer to the next highest whole number.

For b), use 50 for sd.

For c), use 95% interval.

For d), use 10 for E.

I hope this will help get you started.

- statistics -
**Anonymous**, Friday, April 24, 2015 at 10:23pm
mn

## Answer this Question

## Related Questions

- statistics - a.a statistics practitioner randomly sampled 100 observations from ...
- Statistics - Calculate the following: a) Determine the sample size necessary to ...
- statistics - Use the given information to find the minimum sample size required ...
- statistics - what are the mean and standard deviation of a sampling distribution...
- statistics - Use the given information to find the minimum sample size required ...
- Statistics - An admissions director wants to estimate the mean age of all ...
- statistics - a. A statistics practitioner randomly sampled 100 observations from...
- Statistics - Which of the following statements correctly interprets a 95% ...
- Math - The mean of a sample of 25 was calculated as xbar = 500. The sample was ...
- statistics - A population has a mean of 300 and a standard deviation of 50. ...