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Math 227 Spring 2009 Instr:Wong Ch3&4 Test Name:___________________________ #1 6pt. Find the standard deviation of 2.8 , 3.2 , 1.4 , 2.0 , 2.6 #2 For the data given below, 12 23 35 9 20 41 53 19 30 28 6 10 3pt. (a) Find the mean 3pt. (b) Find the median 4pt. (c) Find P63 . 4pt. (d) Find the percentile rank of 19. #3 8pt. Based on the data provided for #2 to find the five numbers summary and construct a boxplot. #4 5pt. The quiz scores for Ch2 had a bell-shaped curve distribution. If the mean of the test scores was 13.8 and the standard deviation was 1.4. Would it be unusual for a student to score a 16 on the Ch2 quiz? Use the Empirical rule to explain your conclusion. #5 6pt. Heights of women have a mean of 63.6 in. and a standard deviation of 2.5 in. Use the Chebyshev's theorem to approximate the percentage of the heights of women will fall between 56.1 in. and 71.1 in.? #6 6pt. A student scored 86 on a general science test where the class mean and standard deviation were 82 and 8 respectively; he also scored 61 on a psychology test where the class mean and standard deviation were 58 and 3 respectively. In which class was his relative position higher? #7 4pt. The Everlast and Endurance brands of car battery are both labeled as lasting 48 months. In reality, they both have a mean life of 50 months, but the Everlast Batteries have a standard deviation of 2 months, while the Endurance batteries have a standard deviation of 6 months. Which brand is the better choice? Why? Everlast Batteries: x 50 , x 48, s 2 Endurance Batteries: x 50 , x 48, s 6 #8 1pt. each True/False ______________ (a) The standard deviation, s, is not effected by extreme data. ______________ (b) If the data distribution is skewed to one-side, x should be used for the center of measurements. ______________ (c) 5/4 cannot be an answer for a probability. ______________ (d) On a five possible answers multiple-choice question, the probability of answering the question correctly by random guessing is 1/2. ______________ (e) Having kids and being single are mutually exclusive events. #9 4pt. A study of 150 randomly selected American Airlines flights showed that 108 arrived on time. What is the estimated probability of an American Airlines flights arriving late? #10 4pt. A card is selected randomly from a deck of cards, what is the probability that a face card (Jack, Queen, King) or a club will be selected #11 6pt. Two dice are tossed. What is the probability of getting a sum of 8? #12 Listed below are the Titanic mortality data. Men Survived Died Women Boys Girls 332 318 29 27 1360 104 35 18 5pt. (a) If we randomly select someone who was aboard the Titanic, what is the probability of getting a man or a person who survived? 5pt. (b) What is the probability of getting a woman, given the selected person died? #13 5pt. A carton contains 12 eggs, 3 of which are cracked. If we randomly select 2 eggs, one after the other without replacement, what is the probability that both of the cracked eggs are selected? #14 5pt. There are 9 members on the board of directors for a hospital. If they must elect a chairperson, first vice chairperson, second vice chairperson, and secretary, how many different slates of candidates are possible? #15 6pt. A lottery ticket has a color, R = red, B = blue, or G = green, followed by a 1, 2, 3, or 4. List the elements in the sample space. Use the set notation S = { }. #16 6pt. It is claimed that 70% of the residents in a large town approve of the current zoning law. Four residents are to be randomly selected. Find the probability that at least one approves.