Explore BrainMass
Share

# Population Variance, Standard Deviation, Point Estimate

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

Incomes in the thousands of dollars were sampled in one region, they are as follows (1.5, 3.0, 4.2, 5.6, 2.6, 4.1, 0.9, 5.7, 5.4, 2.6). Assume the population is normal.

What is the point estimate of the population mean?

What is the point estimate for the population variance?

Assume the standard deviation of the population is 1.2 (1,200), construct a 90% confidence interval & construct a 95% interval.

Explain the 95% interval.

How does the size of the sample affect the relationship between the sample mean and the population mean?

What is the needed sample size if the researcher wanted to have a 99% confidence interval with an error or margin of 0.5 thousand dollars (\$500)?

https://brainmass.com/statistics/confidence-interval/population-variance-standard-deviation-point-estimate-169345

#### Solution Preview

The detailed step-by-step solution with all formulas and working given in attached solution file.

The final answers are given in the following.

Point ...

#### Solution Summary

This solution finds the point estimate of the population mean and the population variance.

\$2.19