SAT Mc Graw Hill 2011

74 McGRAW-HILL’S SAT

17.2.5 Notice that the question asks for the median
of these numbers, not for their averageor mode.The
median is the “middle” number when the numbers
are listed in order, or the average of the twomiddle
numbers if there are an even number of numbers. Ac-
cording to the table, there are 20 numbers represent-
ing the number of books each child has read:

1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5+, 5+

We don’t know the final two numbers in the list, only
that they are integers greater than 4. That’s okay: to
find the median, we don’t need these last two numbers;
we only need to find the average of the two middle
numbers (the 10thand 11th), which are 2 and 3. There-
fore the median is 2.5.

18. 4 If she took ashots in her first game and made
    50% of them, then she made .5ashots in the first

game. Similarly, she made .6bshots in the second

game. If she made 52% of her shots altogether, then

Cross-multiply: .5a+.6b=.52a+.52b

Subtract .5aand .52b: .08b=.02a

Divide by 0.02b:

(Chapter 7, Lesson 4: Ratios and Proportions)

(Chapter 7, Lesson 5: Percents)

Section 6

1.B Sandra’s father’s words were not thoughtfulor

useful,but rather they were hollow clichés.They were

overusedand thoughtless.

irate=angry; inane=pointless; homogeneous=the same

throughout; flamboyant=lively; altruistic=selfless

2.C If he was courageousin prison, he must not

have given up his fight.

treacherous=deceitful; futile=having no hope of suc-

cess; fortitude=strength; premeditated=planned in

advance; porous=full of holes

3.A Since the teachers couldn’t hear themselves

talk, the construction must have been noisy, and there-

fore was not very constructiveto learning (no pun in-

tended).

din=noise; conducive=helpful, constructive; averse

=opposed to; discernible=detectable; irascible=eas-

ily angered

4.C The sentence implies that solutions to physics

problems are approximate,so they cannot be exact.

The approximate solution would be sufficient as long

as the complicating factors are small.

negligible=not significant; plausibly=with a good

likelihood of success; ethically=with regard to moral

standards

5.D Martial resourcesare those resources that sus-

tain an army’s ability to fight; they are the meansto

continue fighting. If the factions both have accessto

these resources, the fight is likely to drag on.

mediation=attempt to resolve a conflict

6.C Since Jung was modest in his therapeutic

claims(lines 4–5) and cautious(line 11) when con-

sulted by schizophrenics, we can conclude that he

did not yet believe that his therapy worked for all

mentally ill patients.

7.A The sentence indicates that psychoanalysis

could bring abouta psychotic episode.

4 =

a

b

..

.

56

52

ab

ab

+

+

=

15. 81 By guessing and checking positive integers,
    you should be able to see that the only positive inte-
    gers that satisfy the equation are 5 and 4. Therefore
    (x+y)^2 =(5 +4)^2 =81.
    (Chapter 9, Lesson 3: Numerical Reasoning Problems)


16. 10 Five out of the 15 marbles are white. If xmore
    white marbles are added, the probability of choosing
    a white marble is. This fraction must be at

least , so ≥3/5

Cross-multiply: 25 + 5 x≥ 45 + 3 x

Subtract 3x: 25 + 2 x≥ 45

Subtract 25: 2 x≥ 20

Divide by 2: x≥10.

(Chapter 9, Lesson 6: Probability Problems)

()

()

5

15

+

+

x

x

3

5

()

()

5

15

+

+

x

x

NUMBER OF BOOKS READ

DURING SUMMER VACATION

Number of

Books Read

Number of

Students

1

2

3

4

More than

4

4

6

5

3

2