This is a fairly easy half-life problem
Each half-life reduces the radioactive material by one half.
So after 72 hours the radioactive material would have undergone 6 half-lives.
2^6 = 64.
So, there will be one sixty-fourth of the material left.
520 / 64 = 8.125 grams will remain.
radioactive decay is an exponential decay function.
Source:
http://www.1728.org/halflife.htm
The mean proportion is p = 36/120 = 0.3.
The standard deviation of the proportion will be sqrt(p*(1-p)/n) = sqrt(0.3*0.7/120) = 0.0418. We multiply this by the z-score of 1.645 to get a deviation of 0.0688.
Therefore, the confidence interval is (0.3 - 0.0688, 0.3 + 0.0688), which is
(0.2312, 0.3688).
Answer:
x=2
ab=7
bc=5
Step-by-step explanation:
because you do
2x+3 = 4x+3
-3 -3
2x=4x
-2x -2x
x = 2
2x2+3
4+3
=7
4x2-3
8-3
=5
