GRE-Math-Questions-to-Know-by-Test-Day-2nd-Edition_pag234

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366. (C) The new product received 8 ratings of 0, 4 ratings of 1, 8 ratings of 2, 6 ratings of 
3, 19 ratings of 4, and 3 ratings of 5. In an ordered set of n data values, the location of the 
median is the +n 1
2
 position. For these data, +n 1
2
 = +48 1
2
 = 24.5, so the median is halfway 
between the 24th and the 25th data value. From the information in the graph, you can 
determine that the 24th data value = 25th data value = 3, so the median is 3.
367. (B) Refer to Answer 116 for an explanation of percentiles. For the 25th percentile, 
= = =k n R
100
48 25
100
12, an integer. Thus, the 25th percentile is halfway between the 
12th and 13th data values: + =1 2
2
1.5. 
368. (E) Because 60 percent of the employees have salaries that are equal to or less than 
$57,500, 60% of 320 = 192 employees have salaries equal to or less than $57,500. 
369. (D) $57,500 is the 60th percentile, and $48,000 is the 50th percentile. Thus, 10% 
(=	60% – 50%) of 320 = 32 employees have salaries between $48,000 and $57,500.
370. (C) To answer the question, find the mode for each answer choice. Eliminate (A) and 
(E). The scores in these choices have no mode because each score occurs the same number 
of times. Eliminate (B) because the mode for these scores is 96. Eliminate (D) because the 
mode for these scores is 84. Choice (C) is correct. The mode for these scores is 87. 
371. (A) Compute the number of standard deviations from the mean for each exam.
 Exam 1: − = − =exam score mean
standard deviation
75 65
5
2 
 Exam 2: − = − = −exam score mean
standard deviation
87 88
2
0.5 
 Exam 3: − = − =exam score mean
standard deviation
92 86
4
1.5 
 Exam 4: − = − =exam score mean
standard deviation
70 60
10
1 
Exam 5: − = − =exam score mean
standard deviation
90 85
5
1 
 With a score that is 2 standard deviations above the mean, the student performed best 
on Exam 1 relative to the performance of the student’s classmates.
372. (E) A box plot, also called box-and-whiskers plot, graphically displays the following 
(in this order): the minimum value (Min), the 25th percentile (Q1, the lower quartile), the 
median (Med), the 75th percentile (Q3, the upper quartile), and the maximum value (Max) 
of a data set. The interquartile range (IQR), which contains the center 50 percent of the 
data, is the difference between the first and third quartiles = −Q Q3 1 = 12.1 – 8.2 = 3.9.
07_McCune_Answer.indd 225 2/21/22 4:37 PM