FindZα/2for each of the following:

a.= .10

b.= .01

c.= .05

d.= .20

Short Answer

Expert verified
  1. 1.645
  2. 2.576
  3. 1.960
  4. 1.28

Step by step solution

01

ComputingZα/2  when α is 0.10

  1. Whenis 0.10, it means that α2will be equal to 0.05. From the z score table containing the level of significances,the associated critical value of z can be found to be 1.645.
02

Computing Zα/2 when α is 0.01

b. Whenis 0.01, it means that α2will be equal to 0.005. From the z score table containing the level of significances,the associated critical value of z can be found to be 2.576.

03

Computing Zα/2 when α is 0.05

c. Whenis 0.05, it means that α2will be equal to 0.025. From the z score table containing the level of significances, the associated critical value of z can be found to be 1.960

04

Computing Zα/2 when α is 0.20

d. Whenis 0.20, it means that α2will be equal to 0.10. From the z score table containing the level of significances, the associated critical value of z can be found to be 1.28.

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Most popular questions from this chapter

Question: A random sample of n measurements was selected from a population with unknown meanμand known standard deviationσ2. Calculate a 95% confidence interval forαfor each of the following situations:

a. n = 75, X = 28,σ2= 12

b. n = 200, X= 102, σ2= 22

c. n = 100, X= 15,σ2=.3

d. n = 100, X= 4.05, σ2= .83

e. Is the assumption that the underlying population of measurements is normally distributed necessary to ensure the validity of the confidence intervals in parts a–d? Explain.

Question: The mean and standard deviation of a random sample of n measurements are equal to 33.9 and 3.3, respectively.

a. Find a 95% confidence interval for μif n = 100.

b. Find a 95% confidence interval forμ if n = 400.

c. Find the widths of the confidence intervals found in parts a and b. What is the effect on the width of a confidence interval of quadrupling the sample size while holding the confidence coefficient fixed?

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