Question

Currently, Crafting for Fun magazine mails out about 23,000 subscriptions each month. A digital format just became available, so the number of print magazine subscriptions is expected to decline by approximately 8.7% this month. Assuming the same decline continues, you can use a function to approximate the number of print magazine subscriptions in x months.
Write an equation for the function. If it is linear, write it in the form g(x)=mx+b. If it is exponential, write it in the form g(x)=a(b)x.

Answer 1

This is exponential decay. Let x be months and g(x) the number of print subscriptions. Each month the count is multiplied by 1 − 0.087 = 0.913, so

g(x) = 23000(0.913)^x.