I have no clue what I am doing at this point and this is due tomorrow. 7 problems with multiple steps.
7.20 Suppose that events A and B are mutually exclusive with P(A) = 1/2 and P(B) = 1/3
a. Are A and B independent events? Explain how you know.
b. Are A and B complementary events? Explain how you know.
7.34 Two fair coins are tossed. Deï¬ne
A = Getting a head on the ï¬rst toss.
B =Getting a head on the second toss.
A and B= Getting a head on both the ï¬rst and second tosses.
A or B = Getting a head on the ï¬rst toss, or the second toss, or both tosses.
a. Find P(A) = the probability of A = 1/2
b. Find P(B) = the probability of B = 1/2.
c. Using the multiplication rule (Rule 3b), ï¬nd P(A andB) = 1/4
d. Using the addition rule (Rule 2a), ï¬nd P(A or B) = ½ + ½ - ¼ = ¾
7.36 In a recent election, 55% of the voters were Republicans, and 45% were not. Of the Republicans, 80% voted for Candidate X, and of the non-Republicans, 10% voted for Candidate X. Consider a randomly selected voter.
A = Voter is Republican
B = Voted for Candidate
a. Write values for P(A) P(A^C) P(B|A) , and P(B|A^C)
b. Find P(A and B), and write in words what outcome it represents
c. Find P(A^C and B), and write in words what outcome it represents
d. Using the results in parts (b) and (c), ï¬nd P(B).
(Hint:The events in parts (b) and (c) cover all of the ways in which B can happen.)
e. Use the result in part (d) to state what percent of the vote CandidateX received.
8.51 Weights (X) of men in a certain age group have a normal distribution with mean m= 180 pounds and standard deviation s = 20 pounds. Find each of the following probabilities:
a. P(X less then or = to 200) = probability the weight of a randomly selected man is less than or equal to 200 pounds.
b. P(X less then or = to 165) = probability the weight of a randomly selected man is less than or equal to 165 pounds.
c. P(X > 165) = probability the weight of a randomly selected man is more than 165 pounds.
8.58 Find the following probabilities for Verbal SAT test scores X, for which the mean is 500 and the standard deviation is 100. Assume that SAT scores are described by a normal curve.
a. P(X less than or = 500) x=500
b. P(X less than or = 650).
c. P(X greater or = 700).
d. P(500 less than or = X less then or = 700).
9.13 A medical researcher wants to estimate the difference in the proportions of women with high blood pressure for women who use oral contraceptives versus women who do not use oral contraceptives. In an observational study involving a sample of 900 women, the researcher ï¬nds that .15 (15%) of the 500 women who used oral contraceptives had high blood pressure, whereas only .10 (10%) of the 400 women who did not use oral contraceptives had high blood pressure.
a. What is the research question of interest for this study?
b. What is the population parameter in this study? What is the appropriate statistical notation for this parameter?
c. What is the value of the sample estimate (statistic) in this study? What is the appropriate statistical notation for this estimate?
9.66 Explain which parameter is being described in each of the following situations: µ, µd OR µ1- µ2
a. The difference in the mean number of pushups new male and female military recruits can do.
b. The mean change in the number of pushups female recruits can do at the end of basic training, compared with the number at the beginning.
c. The mean grade point average for all students at your school.
d. The difference in the mean age of women who were married for the ï¬rst time in 1950 and women who were married for the ï¬rst time in 2000.
e. The difference in the mean height of college women and the mean height of their mothers.
|Due By (Pacific Time)
||03/10/2015 05:00 pm