SOLUTION: The function f(x)=900(0.5)^x/100 models the amount in pounds of a particular radioactive material stored in a concrete vault, where x is the number of years since the material was

Algebra ->  Functions -> SOLUTION: The function f(x)=900(0.5)^x/100 models the amount in pounds of a particular radioactive material stored in a concrete vault, where x is the number of years since the material was       Log On


   

Question 420451: The function f(x)=900(0.5)^x/100 models the amount in pounds of a particular radioactive material stored in a concrete vault, where x is the number of years since the material was put into the vault. Find the amount of radioactive material in the vault after 90 years. Round to the nearest whole number.
a.) 482 pounds
b.) 405 pounds
c.) 417 pounds
d.) 500 pounds
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+f%28x%29=900%280.5%29%5E%28x%2F100%29+
given:
+x+=+90+
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+f%2890%29=900%280.5%29%5E%2890%2F100%29+
+f%2890%29=900%280.5%29%5E.9+
+f%2890%29=+900%2A.53589+ (using calculator)
+f%2890%29+=+482.3+
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(a) 482