MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Transcription

1 Test I Math 1107 DeMaio Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Find the indicated probability. 1) In a batch of 8,000 clock radios 8% are defective. A sample of 12 clock radios is randomly selected without replacement from the 8,000 and tested. The entire batch will be rejected if at least one of those tested is defective. What is the probability that the entire batch will be rejected? A) B) C) D) ) If a person is randomly selected, find the probability that his or her birthday is in May. Ignore leap years. A) 31 1 B) C) 1 D) ) 2) 3) In one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kwh and a standard deviation of 218 kwh. For a randomly selected home, find the probability that the September energy consumption level is between 1100 kwh and 1225 kwh. A) B) C) D) ) Based on meteorological records, the probability that it will snow in a certain town on January 1st is Find the probability that in a given year it will not snow on January 1st in that town. A) B) C) D) ) In one town, 71% of adults have health insurance. What is the probability that 4 adults selected at random from the town all have health insurance? A) 2.84 B) C) 0.71 D) Use summary statistics to answer the question. 6) Here are some summary statistics for annual snowfall in a certain town compiled over the last 15 years: lowest amount = 10 inches, mean = 41 inches, median = 34 inches, range = 90 inches, IQR = 51, Q1 = 16, standard deviation = 10 inches. Between what two values are the middle 50% of snowfall found? A) 16 and 25.5 B) 16 and C) 16 and 34 D) 16 and 100 E) 16 and 67 Provide a written description of the complement of the given event. 7) Of the thirteen different women Calvin asks for a date, at least one of them accepts. A) All of the women accept Calvin's offer. B) None of the women accept Calvin's offer. C) All but one woman accepts Calvin's offer. 3) 4) 5) 6) 7) 1

2 Find the standard deviation for the given data. Round your answer to one more decimal place than the original data. 8) Christine is currently taking college astronomy. The instructor often gives quizzes. On the past seven quizzes, Christine got the following scores: Compute the standard deviation s. A) 368 B) 350 C) D) ) Solve the problem. 9) Scores on an English test are normally distributed with a mean of 31.5 and a standard deviation of 7.3. Find the score that separates the top 59% from the bottom 41% A) 27.2 B) 33.2 C) 35.8 D) ) For a recent English exam, use the Normal model N(73, 9.2) to find the percent of scores between 56 and 87. Round to the nearest tenth of a percent. A) 90.4% B) 9.7% C) 96.6% D) 3.37% E) 3.2% 11) The plastic arrow on a spinner for a child's game stops rotating to point at a color that will determine what happens next. Determine whether the following probability assignment is legitimate. 9) 10) 11) Probability of... Red Yellow Green Blue A) Legitimate B) Not legitimate 12) In a business class, 33% of the students have never taken a statistics class, 42% have taken only one semester of statistics, and the rest have taken two or more semesters of statistics. The professor randomly assigns students to groups of three to work on a project for the course. What is the probability that the first group mate you meet has studied no more than one semester of statistics? A) 0.42 B) 0.25 C) 0.75 D) 0.33 E) ) The mean weights for medium navel oranges is 9.8 ounces. Suppose that the standard deviation for the oranges is 3.3 ounces. Which would be more likely, an orange weighing 14 ounces or an orange weighing 4.9 ounces? Explain. A) A 4.9 ounce orange is more likely (z = 1.48) compared with an orange weighing 14 ounces (z = 4.24). B) A 14 ounce orange is more likely (z = -1.48) compared with an orange weighing 4.9 ounces (z = 1.27). C) A 4.9 ounce orange is more likely (z = -1.48) compared with an orange weighing 14 ounces (z = 1.27). D) A 4.9 ounce orange is more likely (z = 1.27) compared with an orange weighing 14 ounces (z = -1.48). E) A 14 ounce orange is more likely (z = 1.27) compared with an orange weighing 4.9 ounces (z = -1.48). 12) 13) 2

3 Find the mean for the given sample data. 14) The local Tupperware dealers earned these commissions last month: $ $ $ $ $ $ $ $ $ $ What was the mean commission earned? Round your answer to the nearest cent. A) $ B) $ C) $ D) $ Find the range for the given data. 15) The manager of an electrical supply store measured the diameters of the rolls of wire in the inventory. The diameters of the rolls (in m) are listed below Compute the range. A) B) C) D) Assume that X has a normal distribution, and find the indicated probability. 16) The mean is m = 15.2 and the standard deviation is s = 0.9. Find the probability that X is greater than A) B) C) D) Identify potential outliers, if there are any, in the given data. 17) The weekly salaries (in dollars) of 24 randomly selected employees of a company are shown below. 14) 15) 16) 17) A) 2500, 3700 B) 3700 C) 2500 D) 310, 2500, 3700 E) None Find the median for the given sample data. 18) The distances traveled (in miles) to 7 different swim meets are given below: 22, 24, 39, 45, 65, 68, 84 Find the median distance traveled. A) 39 miles B) 45 miles C) 50 miles D) 65 miles 18) 3

4 Solve the problem. Round your answer, as needed. 19) An Imaginary Poll in January 2005 asked 1243 U.S. adults how likely they were to see a new movie that was coming out in the summer. Here's how they responded: Response Number Will definitely see it 244 Will probably see it 268 Will probably not see it 336 Will definitely not see it 395 Total 1243 Let's call someone who responded that they would definitely or probably see it a "likely viewer" and the other two categories, "unlikely viewer." If we select two people at random from this sample, what is the probability that neither is a likely viewer? A) B) C) D) E) ) There is a huge pile of buttons in which 29% are black, 11% are blue, 17% are orange, 24% are white, and the rest are clear. You close your eyes, choose a button at random, write down what color it is, and then put it back in the pile. What is the probability that the third button you choose is the first one that's clear? A) B) C) D) E) Solve the problem. Round results to the nearest hundredth. 21) The mean height of a basketball team is 6.2 feet with a standard deviation of 0.2 feet. The team's center is 7 feet tall. Find the center's z score. Is his score unusual? A) 3.5, no B) 4.4, yes C) 4, yes D) 3.4, no Find the mode(s) for the given sample data. 22) 90, 25, 90, 13, 25, 29, 56, 90 A) 25 B) 52.3 C) 90 D) 42.5 Solve the problem. Round to the nearest tenth. 23) Based on the Normal model for snowfall in a certain town N(57, 8), how many inches of snow would represent the 85th percentile? A) 48.7 inches B) 65 inches C) 65.3 inches D) 48.5 inches E) 49 inches 19) 20) 21) 22) 23) 4

5 Answer Key Testname: TEST 1 1) D 2) A 3) B 4) A 5) B 6) E 7) B 8) D 9) D 10) A 11) A 12) C 13) E 14) C 15) C 16) B 17) A 18) B 19) D 20) A 21) C 22) C 23) C 5