Review linear modeling

P 49

Warm up

1. John uses 2/3 of a cup of oats per serving to make oatmeal. How many cups of oats does he

need to make 6 servings? 2. The cost of an afternoon movie ticket last year

was $4.00. This year an afternoon movie ticket costs $5.00. What is the percent increase of the ticket from last year to this year?

3. The price of a calculator has decreased from $12.00 to $9.00. What is the percent of decrease?

• 1. The table shows test averages of eight students.

• If x = the U.S. History Test Average, and • y= the Science Test Average, the equation of the

least-squares line for the data is y = 077x + 17.65 and r = 0.87. Discuss eorrelation and causation for the data set

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• 2. The table shows numbers of books read by students in an English class over a summer and the students’ grades for the following semester.

• Find an equation for the line of best fit. Calculate Find and interpret the correlation coefficient Then use your equation to predict the grade of a student who read 7 books.

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• Some students were surveyed about how much time they spent playing video games last week and their overall test averages. The equation of the least-squares line for the data is y = x -2.82x + 87.50 and r = -0.89. Choose True or False for each statement.

• A. The variables are time spent playing• games and test averages. • B. The variables have a negative • correlation. • C. The variables have a negative • weak correlation.

• 2. Consider f(x)= -3v - 12. Choose True or False for each statement.

• A. The slope is -3.B. The y-intercept is -12.

• C. The x-intercept is 4.

• 3. Look at each equation. Does the equation have a solution of x =3?

• Select Yes or No for each statement. • A. 2x – 8 = 19 – 7x • B. – 2(3x – 4) = 10 • C. (– 6x/2) = – 9

• 4. Use your calculator to write an equation for the line of best fit for the following data.

• Calculate and interpret the correlation coefficient. Use your equation to predict the value of y when x = 25.