Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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The heights of adult women are
normally distributed with a mean of 62.5 inches and a standard deviation of 2.5 inches. Determine
between what two heights 68.2% of adult women will fall.
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a. | between 52.5 and 725 | c. | between 57.5 and
67.5 | b. | between 60 and 65 | d. | between 55 and 70 |
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2.
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For a standard normal distribution, what is the mean and standard
deviation?
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3.
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Find the area between the z-scores,
z = 1 and z = 2.
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a. | 2.3% | c. | 34.1% | b. | 15.6% | d. | 47.7% |
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4.
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The D.O.T. collected
data for a particular stretch of I-85 and found that the average speed was 70 mph with a
standard deviation of 15 mph and the distribution is approximately normally distributed. The
actual Speed Limit for the stretch of road is a maximum of 70 mph and minimum of 40 mph. What
percentage of drivers actually drive between 40mph and 70 mph?
a. | 15.9% | c. | 84.1% | b. | 47.7% | d. | 97.7% |
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5.
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Determine the area under the normal
curve between the z-scores, z = -0.8 and 1.6 as shown in the graph.
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a. | 0.267 | c. | 0.733 | b. | 0.684 | d. | 0.786 |
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6.
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If a set of data is normally distributed, what percent of the data has a z-score
that is greater than  ?
a. | 30.9% | c. | 42.1% | b. | 35.2% | d. | 48.4% |
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7.
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A company’s mean salary is
$65,000 with a standard deviation of $6,000. What is the probability that an employee makes between
$70,000 and $80,000?
(Hint: First find the z-score for x =
70000 and x = 8000.) | | | |
a. | .8039 | c. | .5643 | b. | .9938 | d. | .1961 |
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8.
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The weight of a specific type of
male monkey is normally distributed with a mean of 15 pounds and a standard deviation of 3 pounds.
What is the z-score for a monkey weighing 19 pounds?
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9.
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| Using a Standard Normal
Distribution, what z-score has an area of .892 ? |  | | |
a. | 0.108 | c. | 1.237 | b. | 0.814 | d. | 1.654 |
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10.
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A study was being
conducted about birth weights of babies at a local hospital and found the average to be 7.6 pounds
with a standard deviation of 1.3 pounds (the distribution was approximately normal). Many pre-mature
births weights are in the lowest 1% of births. What would be the birth weight associated with
the lowest 1%?
( Hint: First use the invNorm command
in your calculator to find the z-score and then solve for x to find the birth
rate)
a. | 2.32 pounds | c. | 4.58 pounds | b. | 3.98 pounds | d. | 4.87 pounds |
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