Algebra 1A Sample Work Unit 6

Question

20 8
22 7
9. Emily measured the depth of water in a bathtub at two-minute intervals after the tap was turned off and the
stopper released. The table shows her data.
a) Make a scatter plot for the data.
b) Describe the correlation of the scatter plot.
c) What will the approximate depth be at 15 seconds?

Answer 1

a) To make a scatter plot for the data, we need to plot the time intervals (x-axis) and the corresponding water depths (y-axis).

Time (minutes) | Water Depth (inches)
--------------------------------
20 | 8
22 | 7

We can plot these points on a graph. The x-coordinate would represent the time intervals, and the y-coordinate would represent the water depths.

b) From the scatter plot, we can observe that as time increases, the water depth decreases. The points in the scatter plot show a negative correlation.

c) To approximate the depth at 15 seconds, we need to determine the corresponding water depth when 15 seconds is converted to minutes.

15 seconds = 15/60 minutes = 0.25 minutes

We can estimate the approximate depth by drawing a line of best fit through the scatter plot and finding the corresponding y-coordinate at x = 0.25.