Graphing Notes Flashcards
What are graphs useful for?
shows trends, helps to organize and present data
What are the three types of graphs
pie chart, bar graph, line graph
pie chart definition
ideal for displaying data that is parts of a whole
an entire circle graph equals
100%
bar graph definition
compare similar data for several items or events
what are bar graphs useful for
showing single items for many values; can show a comparison between different groups or track changes over time
line graph definition
show any relationship where the dependent variable changes due to changing the independent variable
what are the two types of variables on a line graph
the independent and dependent variable
where is the independent variable plotted
on the x-axis
where is the dependent variable plotted
on the y-axis
what is the independent variable
the variable being manipulated (changed)
what is the dependent variable
the variable that is being measured
What is a best-fit line used for on a line graph
used to show the trend of data on the graph
What is the first rule for using the best-fit line
look at your data points
what is the second rule for using the best-fit line
determine if the graph is a line or a curve
what is the third rule for using the best-fit line
draw your line through as many points as possible while leaving an equal or almost equal amount of points above or below the graph (line or curve)
What does a direct relationship look like and mean about the variables plotted on the graph
when one variable on a graph increases, the other variable increases, making a straight line. this is a linear relationship
What does an indirect relationship look like and mean about the variables plotted on the graph
when one variable on a graph increases, the other decreases, making a straight line. this is a linear relationship
What does an inverse relationship look like and mean about the variables plotted on the graph
If two variables vary inversely, the points make a hyperbola, a curved shape. The line never crosses x or y axis. When variables vary inversely as one variable increases in value, the other decreases
What does a quadratic relationship look like on a graph
If the variables have a quadratic relationship, the points make a parabola on the graph. Parabolas may open upward or downward and vary in width and steepness
interpolating data
reading between data points on a graph
extrapolating data
reading beyond the data points on a graph - estimating
how do you find the slope on a graph
pick two points and use the slope formula
slope formula
m = y2-y1/x2-x1
