For this case we have the following function:
 y = 1.8 ^ x
 The intersection with the y axis occurs when x = 0.
 We have then:
 y = 1.8 ^ 0
 y = 1
 In this case, the intersection with the y-axis represents the original size of the poster.
 Answer:
 the y-intercept of the graph represents:
 the original size of the poster.
