Population Variance, Standard Deviation, Point Estimate
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)?