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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: