Posted by **Joe** on Wednesday, September 30, 2009 at 8:37pm.

A simple random sample of 25 has been collected from a normally distributed population for which it is know that o=17.0. The sample mean has been calculated as 342.0, and the sample standard deviation is s=14.9. Construct and interpret the 95% and 99% confidence intervals for the population mean.

- statistics -
**MathGuru**, Thursday, October 1, 2009 at 10:44am
CI95 = mean + or - 1.96(sd divided by √n)

...where + or - 1.96 represents the 95% confidence interval using a z-table, sd = standard deviation, √ = square root, and n = sample size.

For the 99% confidence interval, you will have to substitute the value from a z-table that corresponds to 99%.

Put the values you are given from the problem into the formula and go from there to determine your confidence intervals.

I hope this will help get you started.

## Answer This Question

## Related Questions

- statistics - A simple random sample of 25 has been collected from a normally ...
- Statistics - A simple random sample of 25 has been collected from a normally ...
- Statistics - Are these statements true or false? 1. The sample mean, the sample ...
- statistics - A simple random sample of a size n is drawn from a population that ...
- statistics - a simple random sample will be obtained from a normally distributed...
- statistics - A specific study found that the average number of doctor visits per...
- statistics - Determine the 90% confidence interval for a sample, taken from a ...
- statistics - Determine the 90% confidence interval for a sample, taken from a ...
- statistics - A specific study found that the average number of doctor visits per...
- statistics - from a normally distributed infinite number of iron bars lengths ...

More Related Questions