Sewanhaka High School
Math 8
Per:______________
Name:___________________________________
Mrs. Lidowsky, Principal
Mr. Long, Teacher
Date:________________________
H.W. #68: Ditto
DO-NOW #68: Answer the following questions:
1) Make a scatter plot based on the table located at the left. Does the data
displayed on the graph resemble a line rising from left to right, a line falling
from left to right, or neither (does not appear to rise or fall)?
2) Find the equation of a line with the points (8, 30) and (11, 48).
Topic: Statistics
Main Idea: Best Fit Lines
Aim:
RECALL
NOTES
Maurizio had to do a S.S. project on minimum wages
from 1980 to 2000 for Mr. Reid. He put the information
he found into the following table:
YEAR
WAGE ($ per
hour)
1980 1981 1990
$3.10 $3.35 $3.80
YEAR
WAGE ($ per
hour)
1996 1997 2000
$4.25 $4.75 $5.15
Develop the information from the table into a scatter plot.
Does the data displayed on the graph resemble a line
rising from left to right, a line falling from left to right, or
neither (does not appear to rise or fall)?
Statement: Using a ruler and pencil, position the ruler so
that the plotted points are as close to the ruler as possible.
Draw your line of best fit through the points. Have it start
from the y-axis and extend to the other side of the graph.
Question: Predict the minimum wage for the year 2006.
Write an equation in slope-intercept form for the best fit
line for the previous graph.
Using your equation for the best fit line, predict the
minimum wage for the year 2006
Definition: Predicting:
- If you are looking for values that fall within the plotted values, you are interpolating.
- If you are looking for values that fall outside the plotted values, you are extrapolating. Be careful when
extrapolating. The further away from the plotted values you go, the less reliable is your prediction. Predicting the
minimum wage for the year 2006 is an example of extrapolating.
Math 8 – LP #68 – Page 3
Examine the scatter plot below. Draw a line of best fit
through the points. Write an equation for your best fit
line.
Examine the scatter plot below. Draw a line of best fit
through the points. Write an equation for your best fit
line.
Using your equation for the best fit line, predict the arm
span for someone who is 240 cm.
Drill: Answer the following questions. Show work.
1) The scatter plot at the right shows the
number of chapters in a book in relation
to the number of typos found in the
book. If you predict the number of typos
that would occur in a book containing 12
chapters, you would be:
Choose:
extrapolating or interpolating
2) Draw a line of best fit through the points for the graph above. Write an equation for your best fit line.
3) Predict the number of typos that would occur in a book containing 12 chapters.
Summary: