From my knowledge of what an interquartile range is I have to say the answer to your question is 55.5.
<span>60.5 milligrams per square centimeter
First, determine how many half lives have expired by dividing the time by the half-life. So:
55/20 = 2.75
That means that only 2^(-2.75) = 0.148650889 = 14.8650889% of the original substance remains. So just divide the amount remaining by 0.148650889 to get the original amount.
9 / 0.148650889 = 60.5445419
So originally, there was 60.5 milligrams per square centimeter 55 years ago.</span>
Say the width is W and the length is L
L=3W (and of course W=W)
Now you use the perimeter formula P=2L+2W
80=2(3W) + 2W)
80=6W+2W
80=8W Divide both sides by 8
W=10
Now that you know the width, substitute it back into L=3W to find the length
L=3(10)
L=30
The dimensions are length: 30 cm and width: 10 cm
Three consecutive even integers whose sum is -48