Concept explainers
For Exercises 1 through 25, perform each of the following steps.
a. State the hypotheses and identify the claim.
b. Find the critical value(s).
c. Compute the test value.
d. Make the decision.
e. Summarize the results.
Use diagrams to show the critical region (or regions), and use the traditional method of hypothesis testing unless otherwise specified.
9. Telephone Calls A researcher knew that before cell phones, a person made on average 2.8 calls per day. He believes that the number of calls made per day today is higher. He selects a random sample of 30 individuals who use a cell phone and asks them to keep track of the number of calls that they made on a certain day. The mean was 3.1. At α = 0.01 is there enough evidence to support the researcher's claim? The standard deviation for the population found by a previous study is 0.8. Would the null hypothesis be rejected at α = 0.05?
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Elementary Statistics: A Step By Step Approach
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- If the proportion of the population in City A that is over 65 years old is p1 and the proportion of the population in City B that is over 65 years old is p2, what is the null hypothesis for a test to determine if the proportion of the population that is over 65 years old is greater in City A? Select the correct answer below: H0: p1−p2=0 H0: p1−p2>0 H0: p1−p2<0 H0: p1−p2≠0arrow_forwardBased on the data and Anova table, complete the parts of hypothesis testing Ho: ? Ha: ? Alpha: 0.05 F: 6.31 Condition: When to reject Ho? Conclusion?arrow_forwardIn performing a hypothesis T-test, the p-value was 0.00046 and the significance level was 5%. What is the conclusion? Is it a,b,or c? a. Reject the null hypothesis and accept the alternate hypothesis b. Accept both the null hypothesis and alternate hypothesis c. Fail to reject the null hypothesisarrow_forward
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