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

628 APPENDIX A | Basic Mathematics Review
Then perform the multiplication and division:
Finally, do the subtraction:
16 2 14
16 2 14 5 2
A sequence of operations involving multiplication and division should be performed in
order from left to right. For example, to compute 12/2 3 3, you divide 12 by 2 and then
multiply the result by 3:
12/2 3 3 5 6 3 3 5 18
Notice that violating the left-to-right sequence can change the result. For this example,
if you multiply before dividing, you will obtain
12/2 3 3 5 12/6 5 2 (This is wrong.)
A sequence of operations involving only addition and subtraction can be performed in
any order. For example, to compute 3 1 8 2 5, you can add 3 and 8 and then subtract 5:
(3 1 8) 2 5 5 11 2 5 5 6
or you can subtract 5 from 8 and then add the result to 3:
3 1 (8 2 5) 5 3 1 3 5 6
A mathematical expression or formula is simply a concise way to write a set of instructions.
When you evaluate an expression by performing the calculation, you simply follow
the instructions. For example, assume you are given these instructions:
1. First, add 3 and 8.
2. Next, square the result.
3. Next, multiply the resulting value by 6.
4. Finally, subtract 50 from the value you have obtained.
You can write these instructions as a mathematical expression.
1. The first step involves addition. Because addition is normally done last, use
parentheses to give this operation priority in the sequence of calculations:
(3 1 8)
2. The instruction to square a value is noted by using the exponent 2 beside the value
to be squared:
(3 1 8) 2
3. Because squaring has priority over multiplication, you can simply introduce the
multiplication into the expression:
6 3 (3 1 8) 2
4. Addition and subtraction are done last, so simply write in the requested
subtraction:
6 3 (3 1 8) 2 2 50