Chaper 8- Vocabulary

Percentile rank: Indicates the percentage of scores less than or equal to a particular score; is the proportion of scores in a distribution that a specific score is greater than or equal to

Normal curve: A graph resembling a bell-shaped curve

Histogram: A graph that displays the frequency of data

Normal distribution: The frequency distribution of the normal curve

Correlation coefficient: The relationship between two sets of data

Negative correlation: As one variable increases the other decreases, or as one variable decreases the other increases

Positice correlation: As one variable increases so does the other, or as one variable decreases so does the other

R-value: Correlation coefficient

Zero Correlation: The variables have nothing to do with each other, so there is no relation between the two sets of data

Vocabulary- Chapter 6

Relationship: In mathematics a relationship is a connection between two variables; changing the value of one of the variables changes the value of the other

Variable: Letter or symbol used to represent a quantity that can change

Variation: A relationship between two variables, which can be expressed as a formula, a table of values, or as a graph

Direct variation: The relationship between two variables x and y with the form y= kx where k is a constant. A direct variation may be represented by a straight line graph which passes through the origin

Constant of variation: The value of k in the direct variation formula y= kx. K is equal to the slope of the line when the variation is graphed

Directly proportional: Means the same as varies directly

Y varies directly as x: Gives the formula y= kx for variation constant, k

Fixed cost: A cost that remains constant

Partial variation: The relationship between two variables x and y with the form y= kx + F where k is the constant of variation and F is a fixed number. A partial variation may be represented by a straight line graph with slope k and which passes through the point

Variable cost: A cost that changes depending upon the amount of goods purchased.

Direct squared variation: A relationship between two variables which can be written in the form y -kx squared where k is a constant. The shape of a graph showing this variation will be curved. The curve will begin at the origin.

Varies directly as the square: Y varies directly as the square of x gives the formula y= kx squared with constant of variation, k.

Inverse variation: A relationship between two variables which can be written in the form, where k is a constant. A graph showing this variation decreases as you move to the right along the horizontal axis.