Question

Choose the situation which would best be modeled by an exponential decay function.
Responses

A An island is being eroded away and loses 10% of its beachfront every year.An island is being eroded away and loses 10% of its beachfront every year.

B A player's batting average decreases by .025 for each year he is in the major leagues.A player's batting average decreases by .025 for each year he is in the major leagues.

C A bank account has fallen below a minimum balance and is being charged $1.50 per day in fees.A bank account has fallen below a minimum balance and is being charged $1.50 per day in fees.

D A machine depreciates (loses value) by $1000 in its first year, by $2000 in its second, $3000 in its third, etc.

Answer 1

A. It decreases by a fixed percentage (10%) each year, which is multiplicative and thus exponential decay.