Key Concepts

• To round a decimal number, locate the given place value. If the digit to the right of the given place value is greater than or equal to [latex]5[/latex], add [latex]1[/latex]. Otherwise, do not change the digit in the given place value. Rewrite the number, removing all digits to the right of the given place value.
• To convert a percent to a fraction, write the percent as a ratio with the denominator [latex]100[/latex]. Simplify the fraction if requested.
• To convert a percent to a decimal, move the decimal point two places to the left and remove the [latex]%[/latex] symbol.
• To convert a decimal to a percent, move the decimal point two places to the right and insert a [latex]%[/latex] symbol.
• To convert a fraction to a percent, convert the fraction to a decimal by dividing the numerator by the denominator. Then convert the decimal to a percent.
• The Percent Equation: [latex]\mathrm{Percent} \cdot \mathrm{Base} = \mathrm{Amount}[/latex]

Glossary

amount: part of the whole

base: the whole amount

percent: a ratio whose denominator is [latex]100[/latex]

descriptive statistics: a way of describing or showing summaries about data, typically in graphs or numbers

inferential statistics: a way to draw conclusions from “good” data. For example, if the data are representative of a population, then conclusions can be drawn about the population