In 1950, the use of coal in the US was 114.6 million tons. The use of coal has decreased by 6.6% per year since then. Estimate the amount of coal used in the US in 2010. Round to the nearest tenth of a million tons.

Question

Mathematics

Baron Neal

1 October, 20:54

In 1950, the use of coal in the US was 114.6 million tons. The use of coal has decreased by 6.6% per year since then. Estimate the amount of coal used in the US in 2010. Round to the nearest tenth of a million tons.

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Kathryn Arias · Answer 1

The exponential function

c (x) = 114.6 * (1 - 0.066) ^x

evaluates to about 1.9 (million tons) for x = 60 years after 1950.

The amount of coal used in the US in 2010 is estimated at 1.9 million tons.