1.A sample of 300 Americans is composed of 200 women and 100 men. What is the standard error of the proportions for the female population?

2.A sample of 150 U.S. adults is composed of 100 women and 50 men. Estimate the confidence interval for the male population with 99% confidence.

3.In a survey sample of 83 respondents, the mean number of hours worked per week is 39.04, with a standard deviation of 11.51. The sample size is 83. Estimate the value of the standard error.

4.In a survey sample of 83 respondents, about 30.1% of the sample work less than 40 hr per week. What is the estimated standard error of the proportion for this group?