Study Guide for Test over Scatter Plots and Linear Models

Letter a was incorrect because it was not in the middle of the data​

​While letter b hit some data points, it still was not in the middle of the data

​Wrong answers

​Same number of data points above the line as below- or close

​Line needs to hit a couple of data points

​Qualifications

Some text here about the topic of discussion

1. Pick two data points on your line

2. Find the change in y over the change in x.​

​The answer is 20/3- remember set up your table

y 40 20​ Change y 20

x 3 0​ Change x 3 so slope is 20/3

​The y-intercept is a (0,20) so b=20. Remember where x is 20 that is our y-intercept. We also know our slope is 20/3. Now we are ready to write our equation in y=mx + b form.

​Did you get get y=20/3x + 20? Is so, you are correct! Good Job!

​

​The answer is 53 because we used the equation. Just replace x with 5 and solve

y= (20/3)(5) + 20

y= ​100/3 + 20 which is approximately 53!

​When using your scatterplot, refer to your line of best fit. That is why the answer will be between 7 and 8 minutes- like 7.5 or 7.6 minutes.

​The answer is 4s + 5p = T or is could also be

T= 4s +5p. Standard form is ax +​ by=c so both variables are on one side of the equation.

​The answer is T= .50c + 1.25d. The c is for the candy bar and the d is for the drink.

​Your answer may have varied a little and still been correct, but I have the answer as

.01p + .05n= $1.42​

​Graph the equation 3x -6y=12

1. Find x intercept 3x = 12, x= 4

2. Find y intercept -6y= 12, y= -2

3. Connect the intercepts on the graph

   with a line.

​

• Remember y is zero at the x-intercept

• x is zero at the y- intercept​

​-2x + 5y = -10

The answer is b because....

x intercept -2x = -14 and -14/-2 is positive 5

y intercept 7y = -14 and -14/7 is -2​

​So the correct answer- drawn in is after you identify the x and y intercepts on your graph, draw a "straight" :( line.

​

Graph of equation

-2x + 5y = -10​

​x + 2y = 2

x intercept is x =2

y intercept is 2y=2 so y = 1​

​Remember the TOTAL is in the bottom

right hand corner- 50!

​12 means there are 12 girls who like French.

​There was a total of 30 girls interviewed!

​The answer is 1/2 because 10 out of 20 boys like Spanish but don't forget.... reduce your answer!

​You answer should be 3/5. This is reduced from 15/25.