FM Dept Review Part 2 - Faculty Web Pages

Lial 9 th Edition
FM Dept Review P2 F09
53. For the following set of numbers, find the median. 14, 16, 27, 12, 27, 17, 13 9.1.15
54. For the following set of numbers, find the mode. 67, 69, 67, 75, 69, 64, 71
If there is more than one mode, use a comma to separate the numbers. If there is no mode, write N for
your answer. 9.1.25
55. An assembly-line machine turns out washers with the following thicknesses (in millimeters). Find the mean
and standard deviation of the thicknesses. Round your answers for the mean to 4 decimal places. Use that
answer to find the standard deviation rounded to four decimal places. 9.2.27
1.65, 1.21, 1.37, 1.93, 1.86, 1.38, 1.69, 1.56, 1.22, 1.77, 1.28, 1.98, 1.99, 1.96, 1.42, 1.71
56. Suppose that the life expectancy of a certain brand of non-defective light bulbs is normally distributed, with
a mean life of 1300 hours and a standard deviation of 50 hours. If 90,000 of these bulbs are produced, how
many can be expected to last less than 1365 hours? 9.3.23
57. An “average” jar of peanut butter contains 442 g with a standard deviation of 10.2g. Find the probability that
a jar contains less than 430 g. Assume a normal distribution. Round your answer to four decimal places as
needed. 9.3.40
58. Suppose that 1000 coins are tossed. Find the probability of getting exactly 505 heads. Use the normal
curve approximation to the binomial distribution. 9.4.7
59. The probability that a part produced by a certain factory’s assembly line will be defective is 0.025. Suppose
a sample of 130 parts is taken. Find the following probabilities by using the normal curve approximation to
the binomial distribution. 9.4.17
a. Exactly 5 defectives
b. No defectives
c. At least 1 defective
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