 |
| This is an ordinary scatter plot graph consisting of data gathered and the line going through the plotted data is known as the "line of best fit" and is used to find an average slope (rise over run) of the data so that an equation can be made to predict either the Price with however many Units Solid or how many Units Solid with a certain price. The "line of best fit" is self determined on where you feel the most average of the information gathered is. Notice: the line goes down the middle of the cluster of plotted dots to show an approximate average. |
- Daily Objective: Students will use the line of best fit to find equations of lines.
- Definition: Students will learn and know how to find and apply equations of a line; the line will be a line of best fit placed in a scatter plot and drawn based on the approximate average between the plotted data.
- How: Your line of best fit should go through 2 or more plotted dots. The coordinates of two of the plotted dots you choose will be applied to the following formula:
- m=slope in the equation y=mx+b
- Now you apply slope and one of your plotted coordinates used in the above equation, into y=mx+ b and this should give you the answer to b.
- Now insert your answers into y=mx+ b so that
it looks like y= # (x) +/- #
QUIZ
1)
Determine the equation of the line of best fit for the graph shown.
2)
The points with coordinates (0, 6), (2, 7), (4, 8) and (6, 9) lie on a straight line.
Use the equation (from 1) to estimate y when x = 4.
1)The intercept and the gradient can be found from the graph, as shown on the following diagram. (Note that the scales on the vertical and horizontal axes are not the same.)
| c = 5, | m = |
| = |
|
| so the line of best fit has equation | y = |
| x + 5. |
2) The points and the line are shown on the graph.
The intercept is 6.
| The gradient = |
| = |
| , so the equation of the line is |
| y = |
| x + 6 |
3) Substitute x = 4 into the equation.
| y | = |
| × 4 + 5 | = | 2 + 5 | = | 7 |
No comments:
Post a Comment