At
--PLEASE BE SURE TO SHOW ALL ACTUAL CALCULATIONS INVOLVED--
A.
In a study of high school students at least 16 years of age, researchers obtained the survey results summarized in the table below:
|
Irregular Seat Belt Use?
|
|
Yes
|
No
|
Texted While Driving
|
1737
|
2048
|
Did not Text While Driving
|
1945
|
2775
|
(1) State the null and alternative hypotheses for the above study.
(2) Assuming independence, what are the expected frequencies for each of these variables?
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(3) What is the value of the
X
2
statistic?
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(4) Use a 0.05 significance level to test the claim of independence between texting while driving and irregular seat belt use. Are those two risky behaviors independent of each other?
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B.
The Carolina Tobacco Company advertised that its best-selling, non-filtered cigarettes contained 40 milligrams of nicotine or less, but
Consumer Advocate
magazine ran tests on 10 randomly selected cigarettes and found the following amounts (in milligrams), shown below:
47. 3 39.3 40.3 38.3 46.3 43.3 42.3 49.3 40.3 46.3
(5) We can assume that the amount of nicotine in all cigarettes is normally distributed?
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(6) Use a significance level of 0.05 to test the magazine’s claim that the mean nicotine content of the Carolina Tobacco Company’s cigarettes is greater than 40 milligrams.
Show all calculations involved.-I have also attached a copy of this assignment-