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Quesyion C Use the sample information x-37, 5 15 to calculate the following conf

ID: 3068781 • Letter: Q

Question

Quesyion C

Use the sample information x-37, 5 15 to calculate the following confidence intervals for assuming the sample is from a normal population. (a) 90 percent confidence. (Round your answers to 3 decimal places.) The 90% confidence interval is from/ 34.876 to 1 39.124 (b) 95 percent confidence. (Round your answers to 3 decimal places.) The95% confidence interval is from 34 470 to | 39.530 (c) 99 percent confidence (Round your answers to 4 decimal places.) The 99% confidence interval is from to (d) Describe how the intervals change as you increase the confidence level The interval gets narrower as the confidence level increases The interval gets wider as the confidence level decreases The interval gets wider as the confidence level increases The interval stays the same as the confidence level increases eBook & Resources

Explanation / Answer

Sample size n = 15
Sample mean X = 37
Sample standard deviation = 5
Z value for 99% confidence level = 2.575

= 37 ± 2.575(5 / 15)

= 37 ± 2.575 x 1.291
= 37 ± 3.3243
37 + 3.3243 = 40.3243 or 37 - 3.3243 = 33.6757
The lower limit is 33.6757 and
The upper limit is 40.3243