The Population Variance and Standard Deviation Speech or Presentation

The Population Variance and Standard Deviation - Speech or Presentation Example The standard deviation of the sample was 4.1 million. Find the 95% confidence interval of the true mean. Â  12. It has been reported that 20.4% of incoming freshmen indicate that they will major in business or a related field. A random sample of 400 incoming college freshmen was asked their preference, and 95 replied they were considering business major. Estimate the true proportion of freshmen business majors with 98% confidence. Does your interval contain 20.4? Â  16. A recent study indicated that 29% of the 100 women over age 55 in the study were widows. How large a sample must you take to be 90% confident that the estimate is within 0.05 of the true proportion of women over age 55 who are widows? Â  8. Find the 90% confidence interval for the variance and standard deviation of seniors at Oak Park College if a sample of 24 students has a standard deviation of 2.4 years and the variable is normally distributed. What would be the 95% confidence interval? Â  12. The percentage rates of home ownership for 8 randomly selected states are listed below. Estimate the population variance and standard deviation for the percentage rate of home ownership.