Find the area under the standard normal curve to the left of z = 1.25.
A) 0.2318 B) 0.1056 C) 0.7682 D) 0.8944
Q. 2A medical school claims that more than 28 of its students plan to go into general practice. It is found that among a random sample of 130 of the school's students, 39 of them plan to go into general practice.
Find the P-value for a test of the school's claim.
A) 0.0026 B) 0.9974 C) 0.0052 D) 0.1635
Q. 3The partially filled contingency table gives the frequencies of the data on age (in years) and sex from the residents of a retirement home.
Age (yrs)
60-69 70-79 Over 79 Total
Male 14 9 5
Female 6 2 4
Total
What percentage of residents are female ?
A) 31 B) 30.4 C) 30 D) 29.5
Q. 4Dave drives to work each morning at about the same time. His commute time is normally distributed with a mean of 46 minutes and a standard deviation of 5 minutes.
The percentage of time that his commute time exceeds 58 minutes is equal to the area under the standard normal curve that lies to the ___ of ___.
A) right, 2.4 B) left, 1.2 C) right, 12 D) left, 2.4
Q. 5A researcher wishes to estimate the proportion of all drivers who exceed the speed limit on a certain stretch of road where accidents frequently happen. Obtain a sample size that will ensure a margin of error of at most 0.
022 for a 92 confidence interval.
A) 20 B) 904 C) 35 D) 1582
Q. 6Dave drives to work each morning at about the same time. His commute time is normally distributed with a mean of 49 minutes and a standard deviation of 8 minutes.
The percentage of time that his commute time lies between 41 and 65 minutes is equal to the area under the standard normal curve between ___ and ___.
A) -1.5, 1.5 B) 0, 1 C) -1, 2 D) -0.5, 2.5
Q. 7True or False: The proportion of the population that has certain characteristics is the same as the probability that a randomly selected individual of the population has these same characteristics.
A) False B) True
Q. 8A company manufactures batteries in batches of 24 and there is a 3 rate of defects. Find the standard deviation for the random variable X, the number of defects per batch.
A) 0.833 B) 0.818 C) 0.849 D) 0.836
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