Answer: B. This student's test grade was 2.4 standard deviations above the mean test grade.
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Explanation:
The z score tells us how far away the raw score is from the mean. This distance is in terms of standard deviations.
- z = 1 means we're 1 standard deviation above the mean
- z = 2 means we're 2 standard deviations above the mean
and so on.
Negative z scores indicate the raw score is below the mean.
- z = -1 means we're 1 standard deviation below the mean
- z = -2 means we're 2 standard deviations below the mean
and so on. So that's why z = 2.4 indicates the students test grade was 2.4 standard deviations above the mean.
Make two equations. Then solve. Let t and b represent the numbers of pages in the Tax Code and Bible, respectively.
t - b = 18,528 . . . . . tax code exceeds Bible by 18,528 pages
t + b = 21,472 . . . . .together, they total 21,472 pages
Add the two equations.
2t = 40,000
t = 20,000
The number of pages in the tax code is 20,000.
The use of grouping symbols in math shows us which part of the problem or expression should be done first. Brackets, braces and parentheses are common grouping symbols used in mathematics. If no symbol is shown between brackets, forexample, (3+7)(8+1) it means that you should multiply after simplifying the operations inside the brackets.