Why do we use degrees of freedom in the second question and not in the first to find the critical value?
Why do we use degrees of freedom in the second question and not in the first to find the critical value?
In a random sample of 190 men, 120 said they used seat belts. In a random sample of 280 women, 50 said they used seat belts. Test the claim that women are less safety-conscious than men are. Using a significance level of 0.05.
a) Identify the claim and state the hypotheses.
b) What is the test statistics? Find the critical values (s).
c) Make the decision to reject or not reject the null hypothesis. Explain why.
d) Graph your decision and include all the
values. That is, the
rejection region.
e) Set up the formula with the correct numbers for the 95%
confidence interval of the mean number of jobs.
The mean age of a random sample of 20 people who were paying slot machines is 48.7 years, and the standard deviation is 6.8 years. The mean age of a random sample of 30 people who were playing roulette is 55.3 with a standard deviation of 3.2 years. Can it be concluded that the mean of those playing slot machines is less than those playing roulette? Using a significance level of 0.05.
a) Identify the claim and state the hypotheses.
b)What is the test statistics? Find the critical values (s) .
c) Make the decision to reject or not reject the null hypothesis.
d) Graph your decision and include all the values. That is, the mean, the standard deviation, the critical value(s), the rejection region.
e) Set up the formula with the correct numbers for the 95%
confidence interval of the mean number of jobs.
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