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# Percents and Averages for Armed Services Vocational Aptitude Battery (ASVAB) Study Guide (page 3)

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Updated on Jul 5, 2011

1. 67%
2. 0.8%
3. 0.12
4. 0.7825
5. 2.5
6. 64%
7. 9.1
8. 75
9. 50%
10. 300%
11. 100
12. 8
13. 10
14. c.
15. c.
16. c.
17. d.

### Averages

An average, also called an arithmetic mean, is a number that typifies a group of numbers, a measure of central tendency. You come into contact with averages on a regular basis: your bowling average, the average grade on a test, the average number of hours you work per week.

To calculate an average, add up the number of items being averaged and divide by the number of items.
Example: What is the average of 6, 10, and 20?
Solution: Add the three numbers together and divide by 3: = 12

### Shortcut

Here's a shortcut for some average problems.

• Look at the numbers being averaged. If they are equally spaced, like 5, 10, 15, 20, and 25, then the average is the number in the middle, or 15 in this case.
• If there is an even number of such numbers, say 10, 20, 30, and 40, then there is no middle number. In this case, the average is half-way between the two middle numbers. In this case, the average is half-way between 20 and 30, or 25.
• If the numbers are almost evenly spaced, you can probably estimate the average without going to the trouble of actually computing it. For example, the average of 10, 20, and 32 is just a little more than 20, the middle number.
Try these average questions.
1. Bob's bowling scores for the last five games were 180, 182, 184, 186, and 188.What was his average bowling score?
1. 182
2. 183
3. 184
4. 185
5. 186
2. Jackson averaged 45 miles an hour for the three hours he drove in town and 60 miles an hour for the three hours he drove on the highway. What was his average speed in miles per hour?
1. 26
2. 48
3. 105
3. There are 10 females and 20 males in a history class. If the females achieved an average score of 85 and the males achieved an average score of 95, what was the class average? (Hint: don't fall for the trap of taking the average of 85 and 95; there are more 95s being averaged than 85s, so the average is closer to 95.)
1. 92
2. 95

1. c.
2. d.
3. b.