Find the probability of at least 2 girls in 5 births. Assume that male and female births are equally likely and that the births are independent events.
A) 0.3125 B) 0.8125 C) 0.1875 D) 0.5000
Q. 2A variable whose values are observed by counting something must be a discrete variable.
A) True B) False
Q. 3The legal profession conducted a study to determine the percentage of cardiologists who had been sued for malpractice in the last eight years. The sample was randomly chosen from a national directory of doctors. Identify the individuals in the study.
A) all cardiologists in the directory
B) the doctor's area of expertise (i.e., cardiology, pediatrics, etc.)
C) each cardiologist selected from the directory
D) the responses: have been sued/have not been sued for malpractice in the last eight years
Q. 4A recent survey found that 71 of all adults over 50 wear sunglasses for driving. In a random sample of 60 adults over 50, what is the mean and standard deviation of those that wear sunglasses?
A) mean: 42.6; standard deviation: 3.51482574 B) mean: 17.4; standard deviation: 3.51482574
C) mean: 17.4; standard deviation: 6.52686755 D) mean: 42.6; standard deviation: 6.52686755
Q. 5n = 183, x = 158; 95 level
A) 0.813 to 0.914 B) 0.824 to 0.903 C) 0.814 to 0.913 D) 0.823 to 0.904
Q. 6The probability that an individual has 20-20 vision is 0.12. In a class of 40 students, what is the mean and standard deviation of the number with 20-20 vision in the class?
A) mean: 40; standard deviation: 2.05523721 B) mean: 4.8; standard deviation: 2.05523721
C) mean: 4.8; standard deviation: 2.19089023 D) mean: 40; standard deviation: 2.19089023
Q. 7The possible values of a discrete variable always form a finite set.
A) True B) False
Q. 8Thirty-five math majors, 47 music majors and 51 history majors are randomly selected from 376 math majors, 591 music majors and 267 history majors at the state university. What sampling technique is used?
A) cluster
B) systematic
C) stratified
D) convenience
E) simple random
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