After 2.0 years, the 4.0 mg sample decays to 2.0 mg.
After another 2.0 years (total 4.0 years), the 2.0 mg sample decays to 1.0 mg.
And after another 2.0 years (total 6.0 years), the 1.0 mg sample decays to 0.50 mg.
So it takes 6.0 years for 4.0 mg to decay to 0.50 mg.
In this question we know what the “y-intercept is,so if we go to our graph we can easily just plot the point 7.6 on the y axis of a number line. It also gives you the slope in decimal form so we would want to convert that from 0.2 to 1/5. And remember the slope is how many places you move to get to the next point on the number line. So from the point 7.6 we would move up 1 over 5 to the right because it is a positive number. Your line should run across the upper segment of the number line and your line should make a 20 to 30 degree angle shift