What is the range for 95% and 99%?

For random samples of size n=16 selected from a normal distribution with a mean of   and a standard deviation of  , find each of the following.

The range of sample means that defines the middle  of the distribution of sample means:

The range of sample means that defines the middle   of the distribution of sample means:

Calculate the range for the following set of data:

134, 86, 141, 59, 123, 45
 

What is the z value for a 90, 95, and 99 percent confidence interval?

10. What is the best point estimate of the GWA of all senior high school students?
      A. 85 B. 87 C. 88 D. 89
11. At 99% confidence level, what is the confidence coefficient to be used?
      A. 1.282 B. 1.645 C. 1.96 D. 2.575
12. At 99% confidence level, what is the estimated standard error of the mean? (2 points)
      A. 0.2521 B. 0.2551 C. 0.2567 D. 0.2732
13. At 99% confidence level, what is the margin of error to estimate the GWA of all senior 
high school students? (2 points)
      A. 0.3291 B. 0.4223 C. 0.6610 D. 0.6613
14. At 99% confidence level, what is the interval estimate of the GWA of all senior high 
school students?
      A. 87.3556 - 88.6776 C. 87.5777 - 88.4223
      B. 87.4969 - 88.5031 D. 87.6709 - 88.3291
15. At 95% confidence level, what is the confidence coefficient to be used?
      A. 1.282 B. 1.645 C. 1.96 D. 2.576
16. At 95% confidence level, what is the estimated standard error? (2 points)
      A. 0.2521 B. 0.2551 C. 0.2567 D. 0.2732
17. At 95% confidence level, what is the margin of error to estimate the GWA of all senior 
high school students? (2 points)
      A. 0.3291 B. 0.4223 C. 0.5031 D. 0.6613
18. At 95% confidence level, what is the interval estimate of the GWA of all senior high 
school students?
      A. 87.3387 - 88.6613 C. 87.5777 - 88.4223
      B. 87.5135 - 88.5197 D. 87.6709 - 88.3291
For items 19-21, In preparation for the next school year, the school administrator wants to 
estimate the GWA. If they want to estimate the GWA accurate within an error of 0.75 from 
its true value,
19. What is the estimated population standard deviation?
      A. 2.93 B. 3.33 C. 3.43 D. 3.45
20. What should be the sample size at 99% confidence level? (2 points)
      A. 141 B. 200 D. 375 D. 425
21. What should be the sample size at 95% confidence level? (2 points)
      A. 65 B. 82 D. 92 D. 104