I am struggling with Statistics in all areas. I'm great with numbers, however, I'm lost with this. Can someone help? Here are the following questions on estimates and samples,confidence intervals and critical value:

1.

The confidence interval: 5.06 < sigma2 < 23.33 is for the population variance based on the following sample statistics:

n = 25, x-bar = 41.2, and s = 3.1

What is the degree of confidence? Use only integers, no % sign and no decimal places.

2. Find the margin of error. 95% confidence interval; n = 91 ; x-bar = 55,

s = 5.4

Round to the nearest two decimal places.

3. Find the critical value Chi squared R corresponding to a sample size of 3 and a confidence level of 95 percent.

Round to the nearest three decimal places.

4. Find the appropriate minimum sample size: You want to be 95% confident that the sample variance is within 40% of the population variance. Remember, sample size must be an integer.

Thanks,