Consider two independent experiments. In the first one, 86 trials had 61 successes. In the second one, 68 trials had 18 successes. Find the critical value for a 94% confidence interval for the difference of two proportions. Round to 3 decimal places.

In a sample of 41 men, 25 said that they had less leisure time today than they had 10 years ago. In a sample of 41 women, 31 women said that they had less leisure time today than they had 10 years ago. At a=0.01, is there a difference in the proportions?  find the 99% confidence interval for the difference of the two proportions. Round the answers to three decimal places.

When solving a problem related to one sample and the confidence interval of variance. Suppose the sample size is n. What is the degree of freedom we will use?

For a 95% confidence interval and n=21 give the Chi-squared right value.

If n=15, (x-bar)=37, and s=8, find the margin of error at a 80% confidence level Give your answer to two decimal places.

Sample # 1 and has been provided in the second screenshot (hand written)

A survey is taken of 250 students, and a P of 0.45 is found. The same survey is repeated with 1,000 students, and the same value is found. Compare the two 95% confidence intervals. What is the relationship? Is the margin of error for the second one four times smaller? How much smaller is it?

If n=�=25, ¯x=�¯=45, and s=�=6, find the margin of error E� at a 95% confidence level. Give your answer to at least two decimal places.

If n=23, (x-bar)=47, and s=3, find the margin of error at a 98% confidence level Give your answer to two decimal places.

If n=23, ē(x-bar)=34, and s=2, find the margin of error at a 98% confidence level Give your answer to two decimal places.