# Statistics

posted by .

The confidence interval below for the population variance is based on the following sample statistics: n = 25, x-bar = 31.1, and s = 4.2.

9.29 < standard deviation squared < 42.82

What is the degree of confidence?

• Statistics -

99% is the degree of confidence.

To check:
Use 2.58 to represent 99%. Find the formula for the confidence interval using standard deviation. Remember that standard deviation is the square root of the variance. Substitute what you know into the formula from the information given to check.

• Statistics -

I know the formula. How do you work backwards?

## Similar Questions

1. ### Statistics

Which of the following statements correctly interprets a 95% confidence interval on a population mean?
2. ### Statistics

find the 90% confidence interval for the variance and standard deviation of a sample of 16 and a standard deviation of 2.1 Assume the variable is normally distributed.
3. ### statistics

A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is 15. a) Compute the 95 % confidence interval for the population mean. b) Assume that the same sample mean was obtained from a sample …
4. ### statistics

The Frayed Nerves Anxiety Scale (FNAS) is used to measure the anxiety level of people on a scale from 0 to 1000. Four students were randomly chosen and given the FNAS before their second exam. Their scores were 700, 653, 740, and 707. …
5. ### statistics

A psychologist wants to estimate the variance of employee test scores. A random sample of 18 scores had a sample standard deviation 10.4. Find a 90% confidence 2 interval for the population variance. What assumption, if any, have you …
6. ### statistics

The data below are the ages of a random sample of 8 men in a bar. It is known that the population of ages are normally distributed with a standard deviation of 11. Determine the 93% confidence interval estimate of the population mean. …
7. ### Statistics

A 95% confidence interval for a population mean, ?
8. ### Math Statistics

5. Students in an introductory statistics class were asked to report the age of their mothers when they were born. Summary statistics include Sample size: 36 students Sample mean: 29.643 years Sample standard deviation: 4.564 years …
9. ### Statistics

The standard deviation for a population is σ = 15.3. A sample of 36 observations selected from this population gave a mean equal to 74.8. a) Make a 90% confidence interval for μ b) Construct a 95% confidence interval for …
10. ### Statistics

The grades in the final exam of a random sample of 25 students produce a standard deviation, s = 9.5. a) Construct a 90% confidence interval estimate for the population variance, . b) Can we infer at 10% level of significance that …

More Similar Questions