At Penny's Pie Shop, it costs $4 for

1
4
of a pie. What is the cost of a whole pie?
Simplify your answer and write it as a proper fraction, mixed number, or whole number.

To find the cost of a whole pie, we need to know how many fourths are in a whole. Since there are 4 fourths in a whole, the cost of a whole pie is 4 * $4 = $<<4*4=16>>16. So, the cost of a whole pie is $16.