# Lesson 13

Interpreting Points on a Coordinate Plane

Let’s examine what points on the coordinate plane can tell us.

### Problem 1

The elevation of a submarine is shown in the table. Draw and label coordinate axes with an appropriate scale and plot the points.

time after noon (hours) elevation (meters)
0 -567
1 -892
2 -1,606
3 -1,289
4 -990
5 -702
6 -365

### Problem 2

The inequalities $$h > 42$$ and $$h< 60$$ represent the height requirements for an amusement park ride, where $$h$$ represents a person's height in inches.

Write a sentence or draw a sign that describes these rules as clearly as possible.

(From Unit 7, Lesson 8.)

### Problem 3

The $$x$$-axis represents the number of hours before or after noon, and the $$y$$-axis represents the temperature in degrees Celsius.

1. At 9 a.m., it was below freezing. In what quadrant would this point be plotted?

2. At 11 a.m., it was $$10^\circ \text{C}$$. In what quadrant would this point be plotted?

3. Choose another time and temperature. Then tell the quadrant where the point should be plotted.

4. What does the point $$(0, 0)$$ represent in this context?

### Problem 4

Solve each equation.

$$3a = 12$$

$$b + 3.3 = 8.9$$

$$1 = \frac{1}{4} c$$

$$5\frac{1}{2} = d+ \frac{1}{4}$$

$$2e = 6.4$$

(From Unit 6, Lesson 4.)