<PRE><B>Question 697460</B>
A scientist has 200 grams of a substance which has half-life of 5yrs. The graph of its decay function is represented by the equation y=ab^x where x is the number of 15 yr periods. What are the values of a and b 
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y = ab^x
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y = 200(1/2)^(t/5)
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y = 200[(1/2)^(1/5)]^t
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a = 200
b = (1/2)^(1/5) 
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Cheers,
Stan H.</PRE>