1. For each pair of variables, do you expect there to be a relationship? That is, do you think a change in one variable is accompanied by a change in the other variable? How do you expect the second variable to change if the first variable is increased?

   

   1. hours of sleep and energy level
   2. length of hair and energy level
   3. number of school events each week and time spent watching videos online each week
   4. temperature and watermelon sales

2. Some data is collected for each pair of variables listed and represented by a scatter plot. For each pair of variables, how do the scatter plots support or contradict your answers from the previous question?

   1.  

      

      Scatter plot on grid, origin O. Horizontal axis, hours of sleep, from 0 to 10. Vertical axis, amount of energy, from 0 to 100, by 10’s. 50 data points. Approximate values 1 comma 10, 1 comma 14, 2 comma 4, 2 comma 5, 2 comma 8, 2 comma 9, 2 comma 22, 2 comma 27, 3 comma 5, 3 comma 18, 3 comma 19, 3 comma 22, 3 comma 25, 3 comma 26, 3 comma 29, 3 comma 37, 3 comma 39, 4 comma 4, 4 comma 12, 4 comma 20, 4 comma 27, 4 comma 33, 4 comma 39, 4 comma 43, 4 comma 47, 5 comma 30, 5 comma 21, 5 comma 28, 5 comma 42, 6 comma 31, 6 comma 53, 7 comma 10, 7 comma 42, 7 comma 59, 7 comma 66, 8 comma 17, 8 comma 20, 8 comma 92, 9 comma 26, 9 comma 54, 9 comma 55, 9 comma 87, 9 comma 96, 10 comma 14, 10 comma 41, 10 comma 43, 10 comma 52, 10 comma 95, 10 comma 98, 10 comma 99.

       
   2.  

      

      Scatter plot on grid, origin O. Horizontal axis, length of hair, inches, from 0 to 12. Vertical axis, amount of energy, from 0 to 100, by 10’s. 50 data points. Approximate values at 0 comma 30, 0 comma 33, 0 comma 49, 0 comma 74, 0 comma 85, 0 comma 93, 1 comma 36, 1 comma 90, 2 comma 29, 2 comma 98, 3 comma 30, 3 comma 44, 3 comma 45, 4 comma 18, 4 comma 19, 4 comma 26, 4 comma 28, 4 comma 28, 5 comma 22, 5 comma 48, 5 comma 57, 5 comma 64, 6 comma 7, 6 comma 21, 7 comma 3, 7 comma 17, 7 comma 48, 7 comma 57, 7 comma 65, 8 comma 11, 8 comma 25, 8 comma 33, 8 comma 57, 8 comma 80, 8 comma 86, 8 comma 96, 9 comma 30,  comma 37, 9 comma 38, 9 comma 53, 9 comma 71, 9 comma 73, 10 comma 32, 11 comma 5, 11 comma 54, 11 comma 60, 12 comma 48, 12 comma 55, 12 comma 67, 12 comma 95.
   3.  

      
   4.  

      

      Scatter plot on grid, Origin O. Horizontal axis, Temperature, degrees Fahrenheit, from 0 to 90 by 10’s. Vertical axis, watermelon sales, dollars, from 0 to 100 by 10’s. Points at 5 comma 14, 5 comma 22, 6 comma 8, 8 comma 5, 10 comma 7, 11 comma 21, 12 comma 7, 14 comma 12, 14 comma 31, 15 comma 17, 15 comma 28, 17 comma 16, 16 comma 17, 18 comma 32, 19 comma 7, 20 comma 0, 21 comma 32, 26 comma 10, 28 comma 20, 28 comma 29, 30 comma 38, 36 comma 20, 42 comma 33, 43 comma 56, 44 comma 54, 47 comma 65, 48 comma 35, 55 comma 69, 58 comma 77, 59 comma 56, 60 comma 41, 60 comma 57, 61 comma 68, 62 comma 50, 62 comma 77, 63 comma 59, 65 comma 53, 68 comma 75, 68 comma 83, 71 comma 87, 72 comma 64, 75 comma 58, 76 comma 67, 80 comma 67, 80 comma 69, 81 comma 78, 85 comma 66, 85 comma 94, 87 comma 95.

Your teacher will give you a set of cards. Take turns with your partner to match each scatter plot with a pair of variables.

1. For each match that you find, explain to your partner how you know it’s a match.
2. For each match that your partner finds, listen carefully to the explanation. If you disagree, discuss your thinking and work to reach an agreement.