500,000,000 would be 5x10 to the 8th power
Answer:
The population is: all glass recycled
The sample is: the 10 selected glass items.
The parameter is the proportion of: all his glass that is clear
The statistic is the proportion of: the selected glass that is clear
Graph-A and graph-D could both accurately show the radioactivity of the sample as the weeks go by. The only difference is that 'A' had 20 units of radioactivity when the time began and 'D' had 40 units. But on both of them, any point on the graph is 1/2 the value of what it was a week earlier ... which is exactly what you expect.
The equation under graph-A is the correct equation of that graph. We don't know anything about the equation under graph-D, because it sank below the bottom of the picture and we can't see it.
The equation of graph-D is
R = 40 (1/2)^x .
If that's not what it says under graph-D, then D is wrong, and only A is a correct answer.