The local police department receives an average of two calls per hour. Use the Poisson distribution to determine the probability that in a randomly selected hour the number of calls is five.
A) 0.0361 B) 0.0018 C) 0.0282 D) 0.0014
Q. 2Find the z-score having area 0.86 to its right under the standard normal curve; that is, find z 0.86 .
A) -1.08 B) 1.08 C) 0.8051 D) 0.5557
Q. 3A psychologist wants to measure the effect of music on memory. He randomly selects 80 students and measures their scores on a memory test conducted in silence.
The next day he measures their scores on a similar test conducted while classical music is playing. The mean score without music is compared to the mean score with music. A) quantitative, dependent B) qualitative, dependent
C) quantitative, independent D) qualitative, independent
Q. 4A university dean is interested in determining the proportion of students who receive some sort of financial aid.
Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial aid. If the dean wanted to estimate the proportion of all students receiving financial aid to within 1 with 90 reliability, how many students would need to be sampled? A) 6546 B) 1584 C) 3980 D) 66
Q. 5Based on 9000 responses from 26,500 questionnaires sent to all its members, a major medical association estimated that the annual salary of its members was 99,000 per year. What sampling technique was used?
A) simple random
B) stratified
C) cluster
D) convenience
E) systematic
Q. 6A help desk receives an average of four calls per hour on its toll-free number. For any given hour, find the probability that it will receive exactly six calls. Use the Poisson distribution.
A) 0.1042 B) 0.0141 C) 725.7202 D) 0.0330
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