Chapter 08, Section 8

Chapter 08, Section 8.2, Problem 013abc

The standard deviation for a population is  σ=6.97. A random sample selected from this population gave a mean equal to 49.42. Determine a  95% confidence interval for  μ assuming  n=196.

Round your answers to two decimal places.

 to 

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Chapter 09, Section 9.1, Problem 007

Write the null and alternative hypotheses for the following example. Determine if the example is a case of a two-tailed, a left-tailed, or a right-tailed test.

To test whether or not a bank's ATM is out of service for an average of more than 10 hours per month.

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Chapter 09, Section 9.1, Problem 008

Write the null and alternative hypotheses for the following example. Determine if it is a case of a two-tailed, a left-tailed, or a right-tailed test.

To test whether the mean starting salary of college graduates differs from 45,000 dollars per year.

H₀:

 dollars
H₁: 

 dollars


This is a 

left-tailed testright-tailed testtwo-tailed test

.

Chapter 09, Section 9.2, Problem 015

Consider H0: μ=72 versus H1: μ>72. A random sample of 16 observations taken from this population produced a sample mean of 76.0. The population is normally distributed with σ=6.

a. Calculate the p-value. Round your answer to four decimal places.

p=

b. Considering the p-value of part a., would you reject the null hypothesis if the test were made at the significance level of 0.01?

Reject.Do not reject.

c. Considering the p-value of part a., would you reject the null hypothesis if the test were made at the significance level of 0.025?

Do not reject.Reject.

the tolerance is +/-2%

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Chapter 09, Section 9.2, Problem 022

Consider H0: μ=100 versus H1: μ≠100.

A random sample of 65 observations produced a sample mean of 99. Using α=0.1, would you reject the null hypothesis? The population standard deviation is known to be σ=12.

Reject the null hypothesis.Do not reject the null hypothesis.

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