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41 . As the degrees of freedom increase in an F distribution, the distribution becomes more nearly normal. Histogram F 2 is closer to a normal distribution than histogram F 1, so the sample displayed in histogram F 1 was drawn from the F _{3,15} population, and the sample displayed in histogram F 2 was drawn from the F _{5,500} population.
42 . Using the calculator function Fcdf, p -value = Fcdf(3.67, 1E, 3,50) = 0.0182. Reject the null hypothesis.
43 . Using the calculator function Fcdf, p -value = Fcdf(4.72, 1E, 4, 100) = 0.0016 Reject the null hypothesis.
44 . The samples must be drawn from populations that are normally distributed, and must be drawn from independent populations.
45 . Let
${\sigma}_{M}^{2}$ = variance in math grades, and
${\sigma}_{E}^{2}$ = variance in English grades.
H
_{0} :
${\sigma}_{M}^{2}$ ≤
${\sigma}_{E}^{2}$
H
_{a} :
${\sigma}_{M}^{2}$ >
${\sigma}_{E}^{2}$
Use the following information to answer the next two exercises: An experiment consists of tossing two, 12-sided dice (the numbers 1–12 are printed on the sides of each die).
1 . Events A and B are:
2 . Find P ( A | B ).
3 . Which of the following are TRUE when we perform a hypothesis test on matched or paired samples?
Use the following information to answer the next two exercises: One hundred eighteen students were asked what type of color their bedrooms were painted: light colors, dark colors, or vibrant colors. The results were tabulated according to gender.
Light colors | Dark colors | Vibrant colors | |
---|---|---|---|
Female | 20 | 22 | 28 |
Male | 10 | 30 | 8 |
4 . Find the probability that a randomly chosen student is male or has a bedroom painted with light colors.
5 . Find the probability that a randomly chosen student is male given the student’s bedroom is painted with dark colors.
Use the following information to answer the next two exercises: We are interested in the number of times a teenager must be reminded to do his or her chores each week. A survey of 40 mothers was conducted.
[link] shows the results of the survey.
x | P ( x ) |
---|---|
0 | $\frac{2}{40}\text{}$ |
1 | $\frac{5}{40}\text{}$ |
2 | |
3 | $\frac{14}{40}\text{}$ |
4 | $\frac{7}{40}\text{}$ |
5 | $\frac{4}{40}\text{}$ |
6 . Find the probability that a teenager is reminded two times.
7 . Find the expected number of times a teenager is reminded to do his or her chores.
Use the following information to answer the next two exercises: On any given day, approximately 37.5% of the cars parked in the De Anza parking garage are parked crookedly. We randomly survey 22 cars. We are interested in the number of cars that are parked crookedly.
8 . For every 22 cars, how many would you expect to be parked crookedly, on average?
9 . What is the probability that at least ten of the 22 cars are parked crookedly.
10 . Using a sample of 15 Stanford-Binet IQ scores, we wish to conduct a hypothesis test. Our claim is that the mean IQ score on the Stanford-Binet IQ test is more than 100. It is known that the standard deviation of all Stanford-Binet IQ scores is 15 points. The correct distribution to use for the hypothesis test is:
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