Question

In the United States between 1910 and 1994, the amount of currency in circulation M ( in billions of dollars) can be approximated by the function M = 2.08 * (1.06) ^ t where t represents the number of years since 1910. Determine the amount of currency in circulation in the year 1980. (round to the nearest hundredth).

A.3.32
B.122.88
C.220.06
D.2.65

Answer 1

B. 122.88

Explanation:

Since t is the number of years since 1910, we can find the t value we need for the equation by subtracting 1910 from 1980:

t = 1980 - 1910 = 70

Now, we can plug in 70 for t to find the amount of currency in 1980:

`M(t)=2.08(1.06)^t\\M(70)=2.08(1.06)^7^0\\M(70)=122.8779348\\M(70)=122.88`

Thus, the amount of currency in 1980 according to the model was $122.88 billion