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Computing Formula Values
To compute formulas correctly, you must remember the rules for order of operations. Operations inside parentheses are completed first. Exponentiation comes before multiplication and division. Addition and subtraction occur after multiplication and division.
When they occur in the numerator or denominator of a fraction, addition and subtraction are treated as if they were in parentheses. Also, expressions under a radical sign are considered to be enclosed by a set of parentheses. Finally, a fraction in a fraction should be enclosed by parentheses as well.
Also, when evaluating formulas, remember that multiplication can be denoted by other than the usual times sign (x). One way is by a dot ( . ), and the other is by adjacent numbers in parentheses.
Exercises: The formulas below are similar to the most common ones that occur in elementary statistics. Compute the values of these formulas. The answers can be found by clicking on "Answers" below.