3. The Statistical Bulletin published by the Metropolitan life insurance company reported 2% of all Americans birth results in twins. If a random sample of 8000 births is taken, find the mean, variance and standard deviation of the number of births that would result in twins.
4. A survey of 30 adults found that the mean age of a personâ€™s primary vehicle is 5.6 years. Assuming the standard deviation of the population is .8 years, find the 95% confidence interval of the population mean.
5. Find everything to the left of Z= 2.42