At a tennis tournament a statistician keeps track of every serve. The statistician reported that the mean serve speed of a particular player was 104 miles per hour (mph) and the standard deviation of the serve speeds was 8 mph.
Assume that the statistician also gave us the information that the distribution of the serve speeds was bell shaped. What proportion of the players serves are expected to be between 112 mph and 120 mph? A) 0.1350 B) 0.270 C) 0.95 D) 0.68
Q. 2the number of calls received at a companys help desk
A) quantitative B) qualitative
Q. 3True or False: Variance is the square root of standard deviation.
A) False B) True
Q. 4True or False: The variance of a population is the arithmetic average of the squared deviations about the population mean.
A) True B) False
Q. 5The legal profession conducted a study to determine the percentage of cardiologists who had been sued for malpractice in the last three years. The sample was randomly chosen from a national directory of doctors.
Identify the individuals in the study. A) each cardiologist selected from the directory
B) the responses: have been sued/have not been sued for malpractice in the last three years
C) the doctors area of expertise (i.e., cardiology, pediatrics, etc.)
D) all cardiologists in the directory
Q. 6A recent study attempted to estimate the proportion of Florida residents who were willing to spend more tax dollars on protecting the Florida beaches from environmental disasters. Forty-two hundred Florida residents were surveyed.
Which of the following is the population used in the study? A) all Florida residents
B) the 4200 Florida residents surveyed
C) the Florida residents who were willing to spend more tax dollars on protecting the beaches from
environmental disasters
D) all Florida residents who lived along the beaches
Q. 7A manufacturer of cellular phones has decided that an assembly line is operating satisfactorily if less than 0.0 5 of the phones produced per day are defective.
To check the quality of a days production, the company decides to randomly sample 10 phones from a days production to test for defects. Define the population of interest to the manufacturer. A) all the phones produced during the day in question
B) the 10 phones sampled and tested
C) the 10 responses: defective or not defective
D) the 0.05 of the phones that are defective
Q. 8Last year batting averages in professional baseball averaged 0.266 with a high of 0.334 and a low of 0.228 (minimum 250 at-bats). Based on this information, which measure of variation could be calculated?
A) range B) variance
C) standard deviation D) percentile
Q. 9The book cost (in dollars) for one semesters books are given below for a sample of five college students. Calculate the sample variance of the book costs. 200, 130, 400, 500, 345
A) 22,450.00 B) 149.83 C) 370.00 D) 315.00
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