Question

Meg plotted the graph below to show the relationship between the temperature of her city and the number of people at a swimming pool: Main title on the graph is Swimming Pool Population. Graph shows 0 to 30 on x axis at increments of 5 and 0 to 12 on y axis at increments of 1. The label on the x axis is Temperature in degree C, and the label on the y axis is Number of People at the Pool. Dots are made at the ordered pairs 2.5, 1 and 5, 2 and 7.5, 2 and 7.5, 3 and 7.5, 4 and 10, 5 and 10, 6 and 12.5, 6 and 15, 7 and 15, 8 and 17.5, 5 and 17.5, 7 and 20, 9 and 22.5, 7 and 22.5, 9 and 25, 11 and 27.5, 12. Part A: In your own words, describe the relationship between the temperature of the city and the number of people at the swimming pool. (5 points) Part B: Describe how you can make the line of best fit. Write the approximate slope and y-intercept of the line of best fit. Show your work, including the points that you use to calculate slope and y-intercept. (5 points)

Answer 1

From the given data above, I used a scatter plot to present my graph using microsoft excel and added a trend line to get the line of best fit. The equation that I got is y = 2.3775x + 1.1011 and the r² = 0.8922.

Part A: The temperature of the city is directly proportional with the number of people at the swimming pool because it showed an r² = 0.8922. Also, the line is linear with first degree.

Part B: You can make a line of best fit by:

1. Plot your data in a graphing paper or excel.
2. Make sure that your plotted data has a solid mark to indicate the points in the graph.
3. Divide your data points by labeling x at the center, at the farthest part of your line (left or right diagonally).
4. If you feel that the data are now finely divided, then construct a line base on the x marks you're placing
5. Then you will notice how far or near your date points are by simply looking at the points near the constructed line that you created.