Bellringer Are sales up or down? How do you know?

Ms. Hanlon’s Science Classes Displaying Data Ms. Hanlon’s Science Classes

Objectives Distinguish between dependent and independent variables. Be able to graph data points. Understand how smooth curves drawn through data points represent the relationship between dependent and independent variables. Recognize linear and direct relationships and be able to find and interpret the slope of the curve. Recognize quadratic and inverse relationships.

Bar Graph A bar graph is used to show relationships between groups. The two items being compared do not need to affect each other. It's a fast way to show big differences. Notice how easy it is to read a bar graph.

Pie Chart A circle graph is used to show how a part of something relates to the whole. This kind of graph is used to show percentages effectively.

Line Graph A line graph is used to show continuing data; how one thing is affected by another. It's clear to see how things are going by the rises and falls a line graph shows.

Dependent vs. Independent Dependent Variable: variable that responds to change in the manipulated variable. Plotted on the vertical (y) axis. Independent Variable: variable that is manipulated or changed in an experiment. Plotted on the horizontal (x) axis.

Linear Relationship Relationship between two variables, x and y, summarized by the equation y = mx + b, where: m = slope If y gets smaller as x gets larger, the slope is negative b = y-intercept the point at which the line crosses the y-axis

Slope

Quadratic Relationship Relationship exists when one variable depends on the square of another. Represented by the equation: y = kx2, where k is a constant. Also known as a parabolic relationship.

Inverse Relationship Relationship between two variables, x and y, summarized by the equation xy = k, where k is a constant. y = k(1/x) = kx-1 Also known as a hyperbolic relationship. Results when one variable depends on the inverse of the other.

Classwork Get into groups by case study assigned. You will have 15 minutes to complete the assignment. Present your case study to the class. Each student must address at least one section of the case study.

Homework Complete the worksheet provided.