Answer
$$(A \circ A)(x)=1.08x$$
$$(A \circ A \circ A)(x)=1.12x$$
$$(A \circ A \circ A \circ A)(x)=1.16x$$
$$( \underbrace{A \circ A \circ \cdots \circ A}_{n \text{ times}} )=(1.04)^nx$$
Work Step by Step
$$(A \circ A)(x)=A(A(x))=1.04(1.04x)=1.08x$$
$$(A \circ A \circ A)(x)=A(A(A(x)))=1.04(1.04(1.04(x)))=1.12x$$
$$(A \circ A \circ A \circ A)(x)=A(A(A(A(x))))=1.04(1.04(1.04(1.04(x))))=1.16x$$
$$( \underbrace{A \circ A \circ \cdots \circ A}_{n \text{ times}} )= \underbrace{A(A( \cdots (A}_{ n \text{ times}}(x)) \cdots ))= \underbrace{1.04(1.04( \cdots ( 1.04}_{ n \text{ times}}(x)) \cdots ))=(1.04)^nx$$