Homework 6

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Provide an appropriate response.
1) A test consists of 10 true/false questions. To pass the test a student must answer at least 7 questions
correctly. If a student guesses on each question, what is the probability that the student will pass
the test?
1)
A) 0.945 B) 0.117 C) 0.055 D) 0.172
2) If an investor purchased 50 shares of Pearson Education stock at $85 per share, 90 shares at $105 per
share, 120 shares at $110 per share and another 75 shares at $130 per share. What is the mean cost
per share?
2)
A) $109.40 B) $130.50 C) $110.25 D) $105.50
3) The register of a college recorded the amount of time each student spent waiting in line during
peak registration hours one Monday. The frequency table below summarizes the results. Find the
standard deviation. Round your answer to one decimal place.
Waiting time
(minutes)
Number of
students
0 – 3 15
4 – 7 15
8 – 11 8
12 – 15 9
16 – 19 0
20 – 23 3
3)
A) 5.4 B) 5.8 C) 5.6 D) 5.3 E) 5.9
4) The frequency distribution below gives the weight in grams of 100 laboratory mice. What is the
probability that the weight of a healthy mouse selected randomly from the sample will be more
than 52 grams?
Weight in grams of Laboratory Mice
Class Interval Frequency
43.5-46.5 16
46.5-49.5 24
49.5-52.5 27
52.5-55.5 24
55.5-58.5 9
4)
A) 0.33 B) 0.23 C) 0.67 D) 0.50
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
A fair coin is tossed fourteen times. What is the probability of obtaining the following? Express the answer both in terms
of Cn, k and as a four–place decimal.
5) Exactly 12 heads? 5)
2
Construct a frequency polygon.
6)
Weight of bag
of chips (in ounces)
Number of
bags
15.6-15.7 6
15.8-15.9 22
16.0-16.1 35
16.2-16.3 27
16.4-16.5 10
6)
Construct a pie graph, with sectors given in percent, to represent the data in the given table.
7)
Favorite Beverage Number of responses
Cola 306
Juice 189
Milk 207
Tea 279
Water 135
7)
Construct the specified histogram.
8) Construct a histogram for the following set of data on oil rig utilization by type.
Oil Rig Type Percentage of Rigs Currently Utilized (Feb. 2004)
Jackup 86%
Semisub 74%
Drill Ship 82%
Submersible 86%
8)
3
Provide an appropriate response.
9) A botanist wants to grow a rare plant in his greenhouse. The probability that a given bulb
will mature is 0.42. Suppose 6 bulbs are planted.
(A) Write the probability function defining this distribution.
(B) What is the probability that 3 or more bulbs will mature?
(Round your answer to three decimal places.)
9)
Which single measure of central tendency – mean, median, or mode – would you say best describes the given set of
measurements? Explain why.
10) 36 41 72 81 64
52 83 78 71 40
10