Math 30-3 Linear Relations
Quizzy
Name: __________________
1. Below each graph, write a description of the trend shown in the scatterplot.
a)
b)
c)
2. A body mass index (BMI) of 25 is the top end of a healthy mass range. The table
compares the mass and height of people with a BMI of 25.
Height
150 160 170 180 190 200
(cm)
Mass
(kg)
56
64
72
81
90
100
a. Create a scatterplot of Mass vs. Height.
100
Mass(kg)
80
60
40
20
150
160
170
180
190
200
Height(cm)
b. Draw a line of best fit for the data on the scatterplot above.
c. Use the line of best fit to estimate the mass of someone who is 155cm tall. Write
the mass below and clearly mark this point on the scatterplot.
d. Use the line of best fit to estimate the height of someone who has a mass of
76kg. Write this height below and clearly mark this point on the scatterplot.
3. Robyn earns $16/h as a lifeguard.
a. Create a table of values to show her total earnings for 0 h to 5 h of lifeguarding.
b. Graph the relationship between Robyn’s total earnings and the number of hours of
lifeguarding.
c. What are the slope and y-intercept of the graph?
d. Is this an example of direct variation or partial variation? Explain how you know.
e. Write an equation that represents the relationship between Robyn’s total
earnings, E, and the number of hours lifeguarding, n.
f. How many hours does Robyn have to lifeguard to earn $40?
4. Cal measures the depth of water in a basin as it drains at a continuous rate. The basin
initially holds 15 cm of water, and, it lowers by 3 cm each minute.
a. What are the initial value and the rate of change?
b. Is this an example of direct variation or partial variation? Explain how you know.
c. Create a table of values that shows the relationship between the number of
minutes and the depth of water over time.
d. Create a graph to show the depth of water over the first 5 min.
e. How many minutes will it take for the basin to drain completely?