Statistics for the Behavioral Sciences by Frederick J. Gravetter, Larry B. Wallnau ISBN 10: 1305504917 ISBN 13: 9781305504912

634 APPENDIX A | Basic Mathematics Review
■ Percentages
1. Converting a Percentage to a Fraction or a Decimal To convert a percentage
to a fraction, remove the percent sign, place the number in the numerator, and use
100 for the denominator. For example,
52% 5 52
100
5% 5 5
100
To convert a percentage to a decimal, remove the percent sign and divide by 100, or
simply move the decimal point two places to the left. For example,
83% 5 83. 5 0.83
14.5% 5 14.5 5 0.145
5% 5 5. 5 0.05
2. Performing Arithmetic Operations with Percentages There are situations in
which it is best to express percent values as decimals in order to perform certain arithmetic
operations. For example, what is 45% of 60? This question may be stated as
45% 3 60 5 ?
The 45% should be converted to decimal form to find the solution to this question.
Therefore,
0.45 3 60 5 27
LEARNING CHECK
ANSWERS
1. Convert 3
25 to a decimal.
2. Convert 3 8 to a percentage.
3. Next to each set of fractions, write “True” if they are equivalent and “False” if they
are not:
a. 3 8 5 9
24 b. 7 9 5 17
19
c. 2 7 5 4
14
4. Compute the following:
a. 1 6 3 7
10 b. 7 8 2 1 2 c. 9
10 4 2 3 d. 7
22 1 2 3
5. Identify the larger fraction of each pair:
7
a. 10 , 21
100 b. 3 4 , 7 22
12 c. 3 , 19
3
6. Convert the following decimals into fractions:
a. 0.012 b. 0.77 c. 0.005
7. 2.59 3 0.015 5 ?
8. 1.8 4 0.02 5 ?
9. What is 28% of 45?
1. 0.12, 2. 37.5% 3. a. True b. False c. True
4. a. 7
60 b. 3 8
c.
27
20
d.
65
66
5. a.
7
10 b. 3 4
c.
22
3
6. a.
12
1000 5 3
250
b.
77
100 c. 5
1000 5 1
200
7. 0.03885 8. 90 9. 12.6