19 terms

Proportional Relationship

two quantities are related by a constant of proportionality (or a constant multiplier)

Rate

A ratio comparing two quantities, often a comparison of time. For example, miles per hour.

Histogram

Similar to a bar graph - each bar represents data in a range of numbers.

Stem-and-leaf plot

Shows the same data as a histogram, but it shows the individual values from a set of data and how the values are distributed.

Quartile

Points that divide a data set into four equal parts

Interquartile Range (IQR)

A way to measure the spread of the data.It is the range of the middle 50% of the data. It is not affected much by outliers or non-symmetrical distributions.

Shape

The overall appearance of the data when it is displayed in a histogram or stem-and-leaf plot. Symmetrical? Uniform? Single peaked? Skewed? Large gaps or clustered?

Outlier

Any data point that is far away from the rest of the data.

Scaling

When a quantity is increased or decreased by a specific proportion of the original amount called the scale factor or multiplier.

Box Plot (or Box-and-Whisker Plot)

A summary of data using the median, quartiles, and extremes of the data. Makes it easy to see where the data are spread out and where they are concentrated.

Fraction Buster

A method of simplifying equations involving fractions that uses the Multiplicative Property of Equality so that no fractions remain. Multiply both sides of an equation by the common denominator of all the fractions in the equation. The result will be an equivalent equation with no fractions.

Constant of Proportionality

The "k" in a proportional relationship, which can be written in the form y = kx

Coefficient

A number multiplied by a variable. For example, -7 is an example of this in the expression −7x.

First Quartile

The median of the lower half of an ordered set of data (Q1)

Third Quartile

The median of the upper half of an ordered set of data (Q3)

Principal

Initial investment or capital. An initial value.

Percent Change

To calculate this:

1. Determine the difference between the two numbers you are comparing.

2. Divide the difference from step 1 by the original number.

3. Multiply by 100.

1. Determine the difference between the two numbers you are comparing.

2. Divide the difference from step 1 by the original number.

3. Multiply by 100.

Rate

A ratio comparing two quantities, often a comparison of time. For example, miles per hour.

Interest

An amount paid which is a percentage of an initial value (principal). For example, a savings account may offer 4% annual interest rate, which means they will pay $4.00 in interest for a principal of $100 kept in the account for one year.