- If a is the standard deviation of b, c, and d, what is the standard deviation
of b + 3, c + 3, and d + 3, in terms of a?
A a
B a + 3
C a + 6
D a + 9
E 3 a - A certain company has only directors and managers. The company has
300 directors and 200 managers. If the average age of the directors is 42
and the average age of the managers is 38, what is the average age of all
the company’s employees?
A 39.8
B 40
C 40.2
D 40.4
E 41 - A student’s average score for 10 tests was x. The grader then discovered
that there was an error on two of the tests. On one of the tests, the
student’s score should have been 10 points lower. On another test, the
student’s score should have been 20 points higher. After the grader
corrects these mistakes, what is the student’s new average, in terms of x?
A x – 1
B x
C x + 1
D x + 10
E x + 20 - What is the average of n, n + 1, n + 7, n + 9, and n + 13, in terms of n?
A n + 2
B n + 3
C n + 6
D n + 8
E n + 15
334 PART 4 ■ MATH REVIEW04-GRE-Test-2018_313-462.indd 334 12/05/17 12:03 pm