# Summary: Review

## Key Concepts

**Convert a percent to a fraction.**- Write the percent as a ratio with the denominator [latex]100[/latex].
- Simplify the fraction if possible.

**Convert a percent to a decimal.**- Write the percent as a ratio with the denominator [latex]100[/latex].
- Convert the fraction to a decimal by dividing the numerator by the denominator.

**Convert a decimal to a percent.**- Write the decimal as a fraction.
- If the denominator of the fraction is not [latex]100[/latex], rewrite it as an equivalent fraction with denominator [latex]100[/latex].
- Write this ratio as a percent.

**Convert a fraction to a percent.**- Convert the fraction to a decimal.
- Convert the decimal to a percent.

**Calculate the mean of a set of numbers.**- Write the formula for the mean [latex]\text{mean}={\Large\frac{\text{sum of values in data set}}{n}}[/latex]
- Find the sum of all the values in the set. Write the sum in the numerator.
- Count the number,
*n*, of values in the set. Write this number in the denominator. - Simplify the fraction.
- Check to see that the mean is reasonable. It should be greater than the least number and less than the greatest number in the set.

**Find the median of a set of numbers.**- List the numbers from least to greatest.
- Count how many numbers are in the set. Call this [latex]n[/latex] .
- Is [latex]n[/latex] odd or even? If [latex]n[/latex] is an odd number, the median is the middle value. If [latex]n[/latex] is an even number, the median is the mean of the two middle values

**Identify the mode of a set of numbers.**- List the data values in numerical order.
- Count the number of times each value appears.
- The mode is the value with the highest frequency.

## Glossary

**percent**- A percent is a ratio whose denominator is [latex]100[/latex] .

## mean

- The mean of a set of [latex]n[/latex] numbers is the arithmetic average of the numbers. The formula is [latex]\text{mean}={\Large\frac{\text{sum of values in data set}}{n}}[/latex]

- median
- The median of a set of data values is the middle value.

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- Revision and Adaptation.
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- Prealgebra.
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