The results of an analysis, on the makeup of garbage, done by the Environmental Protection Agency was published in 1990. Some of the results are given in the following table, which for various years gives the number of pounds per person per day of various types of waste materials. Waste materials
1960
1970
1980
1988
Glass
0.20
0.34
0.36
0.28
Plastics
0.01
0.08
0.19
0.32
Metals
0.32
0.38
0.35
0.34
Paper
0.91
1.19
1.32
1.60

For glass, calculate the average rate of change between 1970 and 1980. Then interpret what this value means.
a.
From 1970 to 1980, the number of pounds of glass per person per day decreased by 0.002 per year.
c.
From 1970 to 1980, the number of pounds of glass per person per day increased by 0.002 per year.
b.
From 1970 to 1980, the number of pounds of glass per person per day decreased by 0.11 per year.
d.
From 1970 to 1980, the number of pounds of glass per person per day increased by 0.11 per year.