TEST 2 REVIEW (STA 2023)

ELEMENTARY STATISTICS (STA 2023) TEST 2 REVIEW Name __________________________________________ Date ______________________ ALL PROBLEMS ARE EQUALLY WEIGHTED 1) Which of the following cannot be a probability? 1) A) - 1 2 B) 2 5 C) 0 D) 1 3 Estimate the probability of the event. 2) Of 1370 people who came into a blood bank to give blood, 251 people had high blood pressure. Estimate the probability that the next person who comes in to give blood will have high blood pressure. 2) A) 0.183 B) 0.151 C) 0.102 D) 0.234 Find the indicated probability. 3) In a poll, respondents were asked whether they had ever been in a car accident. 215 respondents indicated that they had been in a car accident and 449 respondents said that they had not been in a car accident. If one of these respondents is randomly selected, what is the probability of getting someone who has been in a car accident? Round to the nearest thousandth, if necessary. 3) A) 0.479 B) 0.324 C) 0.005 D) 0.676 Answer the question. 4) In a certain town, 10% of people commute to work by bicycle. If a person is selected randomly from the town, what are the odds in favor of selecting someone who commutes by bicycle? 4) A) 1 : 9 B) 1 : 10 C) 9 : 1 D) 9 : 10 Find the indicated complement. 5) Find P(A), given that P(A) = 0.493. 5) A) 1.493 B) 2.028 C) 0.507 D) 0 Find the indicated probability. Express your answer as a simplified fraction unless otherwise noted. 6) The table below shows the soft drinks preferences of people in two age groups. cola lemon - lime Total under 40 years of age 40 20 60 over 40 years of age 25 55 80 Total 65 75 140 If one of the 140 subjects is randomly selected, find the probability that the person is over 40 years of age. 6) A) 5 28 B) 11 28 C) 4 7 D) 3 75 1

Find the indicated probability. 7) The table below describes the smoking habits of a group of asthma sufferers. Nonsmoker Light smoker Heavy smoker Total Men 425 38 35 498 Women 381 32 43 456 Total 806 70 78 954 If one person is randomly selected from the 954 subjects, find the probability that the person is a man or a light smoker. 7) A) 0.556 B) 0.595 C) 0.073 D) 0.034 8) A card is drawn from a well - shuffled deck of 52 cards. Find P(drawing a King or a 3). 8) A) 7 26 B) 2 13 C) 13 2 D) 7 9) In one town, 66% of adults have health insurance. What is the probability that 4 adults selected at random from the town ( with replacement ) all have health insurance? Round to the nearest thousandth if necessary. 9) A) 2.64 B) 0.190 C) 0.66 D) 0.061 10) You are dealt two cards successively ( without replacement ) from a shuffled deck of 52 playing cards. Find the probability that the first card is black and the second card is red. Express your answer as a simplified fraction. 10) A) 1 2,652 B) 25 51 C) 13 51 D) 25 102 Find the indicated probability. Express your answer as a simplified fraction unless otherwise noted. 11) The table below shows the soft drinks preferences of people in two age groups. cola lemon - lime Total under 40 years of age 40 20 60 over 40 years of age 25 55 80 Total 65 75 140 If one of the 140 subjects is randomly selected, find the probability that the person drinks cola given that they are under 40. 11) A) 8 13 B) 2 3 C) 2 7 D) None of the above is correct. Find the indicated probability. Round to the nearest thousandth. 12) An unprepared student makes random guesses for the ten true - false questions on a quiz. Find the probability that there is at least one correct answer. 12) A) 0.999 B) 0.900 C) 0.100 D) 0.001 2

19) A car insurance company has determined that 9% of all drivers were involved in a car accident last year. Among the 14 drivers living on one particular street, 3 were involved in a car accident last year. If 14 drivers are randomly selected, what is the probability of getting at most 3 who were involved in a car accident last year? 19) A) 0.969 B) 0.126 C) 0.094 D) 0.393 Find the mean, μ, for the binomial distribution which has the stated values of n and p. Round answer to the nearest tenth. 20) n = 1665; p = 0.57 20) A) μ = 958.8 B) μ = 956.4 C) μ = 941.6 D) μ = 949.1 Use the given values of n and p to find the minimum usual value μ - 2 Η and the maximum usual value μ + 2 Η . Round your answer to the nearest hundredth unless otherwise noted. 21) n = 1042, p = 0.80 21) A) Minimum: 820.69; maximum: 846.51 B) Minimum: 815.34; maximum: 851.86 C) Minimum: 807.78; maximum: 859.42 D) Minimum: 859.42; maximum: 807.78 Solve the problem. 22) A company manufactures batteries in batches of 28 and there is a 3% rate of defects. Find the standard deviation for the number of defects per batch. 22) A) 81.5 B) 0.9 C) 0.7 D) 0.8 Determine if the outcome is unusual. Consider as unusual any result that differs from the mean by more than 2 standard deviations. That is, unusual values are either less than μ - 2 Η or greater than μ + 2 Η . 23) A survey for brand recognition is done and it is determined that 68% of consumers have heard of Dull Computer Company. A survey of 800 randomly selected consumers is to be conducted. For such groups of 800, would it be unusual to get 634 consumers who recognize the Dull Computer Company name? 23) A) Yes B) No 4

Answer Key Testname: TEST 2 REVIEW (STA 2023) 1) A 2) A 3) B 4) A 5) C 6) C 7) A 8) B 9) B 10) C 11) B 12) A 13) C 14) C 15) D 16) A 17) C 18) B 19) A 20) D 21) C 22) B 23) A 5