Unit 3 Review

What kind of association is this?

• Negative, weak

• positive, strong

• negative, strong

• positive, weak

What kind of association is this?

• Negative, weak

• positive, strong

• negative, strong

• positive, weak

What kind of association is this?

• Negative, weak

• none, strong

• negative, strong

• none, weak

Cory and Anna drew trend lines on the scatter plot shown. Who drew a line that best fits the data?

• cory, he has the correct slope

• anna, she has the correct slope

• cory, he is close to some points

• anna, she is in the middle of most of the points

Write an equation for the trend line shown.

• y = 225x + 25

• y= -25x+225

• y = -5x + 220

• y = 5x + 220

Which of the following could be the equation of a trend line for the scatter plot shown?

• y = -3x-6

• y = -4x+8

• y = 2.5x + 7

• y = x -8

Several schools reported the number of students who received a flu vaccine in a year and the number of cases of the flu amongst their students that year. A scatter plot was made with a trend line that had an equation of y = -0.25 x + 85, where y is the total number of cases of the flu and x is the total number of students who received a flu vaccine. Predict the number of cases of the flu that would occur if 200 students receive a flu vaccine.

• 15

• 20

• 35

• 40

Several schools reported the number of students who received a flu vaccine in a year and the number of cases of the flu amongst their students that year. A scatter plot was made with a trend line that had an equation of y = -0.25x + 85, where y is the total number of cases of the flu and x is the total number of students who received a flu vaccine. Predict how many students received a flu

vaccine if a school had 50 cases of the flu

• 60

• 100

• 140

• 200

Several schools reported the number of students who received a flu vaccine in a year and the number of cases of the flu amongst their students that year. A scatter plot was made with a trend line that had an equation of y = -1/ 4 x + 85, where y is the total number of cases of the flu and x is the total number of students who received a flu vaccine. What is the slope of the trend line equation,

and what does it mean in the context of the

situation?

• there is about one less case of the flu for every 4 students who receive a vaccine

• there is one more case of the flu when 4 students get a vaccine

• there are 4 new vaccines when one students the flu

• there are about four new cases for every student who get the vaccine

Several schools reported the number of students who received a flu vaccine in a year and the number of cases of the flu amongst their students that year. A scatter plot was made with a trend line that had an equation of y = -0.25 x + 85, where y is the total number of cases of the flu and x is the total number of students who received a flu vaccine. What is the y-intercept of the trend line

equation, and what does it mean in the context of

the situation

• we can predict that 85 cases will occur if no students get the vaccine

• if 85 students get the vaccine there will be zero cases

• if there are zero cases then we know 85 people got the vaccine

• there will be 85 cases when zero people get the vaccine