A variable whose possible values are 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, is a continuous variable.
A) True B) False
Q. 2According to insurance records, a car with a certain protection system will be recovered 94 of the time. If 300 stolen cars are randomly selected, what is the mean and standard deviation of the number of cars recovered after being stolen?
A) mean: -618: standard deviation: 16.92 B) mean: 282; standard deviation: 16.92
C) mean: 282; standard deviation: 4.11339276 D) mean: -618: standard deviation: 4.11339276
Q. 3A study was conducted to determine if listening to heavy metal music affects critical thinking. To test the claim, 110 subjects were randomly assigned to two groups. Both groups were administered a basic math skills exam.
The first group took the exam while heavy metal music was piped into the exam room, while the second group took the exam in a silent room. The mean exam score for the first group was 79, and the mean exam score for the second group was 85. The researchers concluded that heavy metal music negatively affects critical thinking. Identify (a) the research objective, (b) the sample, (c) the descriptive statistics, and (d) the conclusions made in the study.
Q. 4In a study, 35 of adults questioned reported that their health was excellent. A researcher wishes to study the health of people living close to a nuclear power plant.
Among 11 adults randomly selected from this area, only 3 reported that their health was excellent. Find the probability that when 11 adults are randomly selected, 3 or fewer are in excellent health.
A) 0.2001 B) 0.2254 C) 0.4256 D) 0.3041
Q. 5A computer manufacturer wishes to estimate what proportion of their laptop computers are defective. Obtain a sample size that will ensure a margin of error of at most 3.5 percentage points for a 95 confidence interval.
A) 785 B) 3137 C) 28 D) 197
Q. 6At a local technical school, five auto repair classes are randomly selected and all of the students from each class are interviewed. What sampling technique is used?
A) simple random
B) stratified
C) cluster
D) systematic
E) convenience
Q. 7A researcher wishes to estimate the proportion of likely voters that will vote for the incumbent. Obtain a sample size that will ensure a margin of error of at most 1 percentage points for a 95 confidence interval.
A) 97 B) 38,416 C) 2401 D) 9604
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