epdf.pub_cbest-cliffs-test-prep13a9b242c7cb4125e6cca92d00a73d5a41681

Symbols, Terminology, Formulas, and General Mathematical Information
Basic Statistics
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To find the arithmetic mean, or average, simply total the numbers and
divide by the number of numbers.
Find the arithmetic mean of 3, 5, 6, 7, and 9. The total is
3+ 5+ 6+ 7+ 9= 30. Then divide 30 by 5, giving a mean, or average,
of 6.
To find the mode, look for the most frequently occurring score or measure.
Find the mode of these scores: 3, 5, 5, 5, 6, 7. The mode is 5 because it
appears most. If there are two modes, the distribution of scores is called
bimodal.
To find the median, arrange the scores or numbers in order by size. Then
find the middle score or number.
Find the median of these scores: 2, 5, 7, 3, 6. First arrange them in order
by size: 7, 6, 5, 3, 2. The middle score is 5; therefore the median is 5.
If the number of scores is even, take the average of the two middle scores.
Find the median of these scores: 2, 5, 7, 4, 3, 6. First arrange them in order
by size: 7, 6, 5, 4, 3, 2. The two middle numbers are 4 and 5; therefore
the median is 4 1 ⁄2.
To calculate the range of a group of scores or numbers, subtract the smallest
from the largest.
Find the range of the scores 3, 2, 7, 9, 12. The range is 12 - 2 = 10.
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