Math Scatter

Julie made 25 international long-distance phone calls to London last month. The scatterplot shows the length and cost of each phone call she made. Which conclusion is best supported by the scatter plot?

• As the length of a call increases, the cost of the call increases.

• As the length of a call increases, the cost of the call remains the same.

• As the length of a call increases, the cost of the call decreases.

• There is no relationship between the length of a call and the cost of a call.

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books. Use the trend line to predict how many pages would be in a book with 6 chapters. 

• ≅100 pages

• ≅170 pages

• ≅60 pages

• ≅20 pages

Which sentence describes the relationship shown on this scatter plot?

• As the temperature decreases, the visitors increase.

• As the temperature increases, the number of visitors increases.

• As the visitors increase, the temperature decreases.

• No correlation

Which scatter plot shows a linear relationship between x and y?

• Graph A

• Graph B

• Graph C

• Graph D

What is the equation of the line of best fit?

• y= 6x + 2

• y = -2x +6

Mrs. Wendel made a scatte rplot to show the relationship between the number of absences and a student’s final exam score. Based on this scatte rplot, a student with 6 absences should get approximately what score on the final exam? 

• 65

• 92

• 70

• 76

Which answer shows a reflection across the x-axis?

• a

• b

• c

• d

Answer explanation

Figure A shows a reflection across the line y=x.

Figure B shows a rotation.

Figure C shows a reflection across the x-axis.

Figure D Shows a reflection across the y-axis.

What axis is the triangle being reflected over?

• X-axis

• Y-axis

Answer explanation

Think of your axis of reflection as a book spine: If you "turn the page" to move your figure from preimage to image, where would the page have been attached?

In this case, the y-axis.

What axis is the image reflected over?

• X-axis

• Y-axis

Answer explanation

Think of your axis of reflection as a book spine: If you "turn the page" to move your figure from preimage to image, where would the page have been attached?

In this case, the x-axis.

Reflections over the x-axis change the ____-__________.

• y-coordinate

• x-coordinate

Answer explanation

If you compare the points in the visual example, you can see that the x-values are the same but the sign of the y-value was changed.

Therefore, reflecting over the x-axis changes the y-coordinate.