Answer
A) The world PV market in 2015 was about $134,057.86\ Mw$ and that of Japan was about $28.42\ Mw$.
B) The percentages are $8.14\%$ 2007 and $0.021\%$ 2015.
Work Step by Step
The problem describes an exponential function with the following parameters.
\begin{equation}
\begin{aligned}
a&= 2826\\
r&= 62\%= 0.62\\
b&=1+r = 1.62
\end{aligned}
\end{equation}
A model of the world solar PV market can be written as:
\begin{equation}
\begin{aligned}
W(t)&=a\cdot b^t\\
&=2826\cdot (1.62)^t
\end{aligned}
\end{equation}
Similarly, for Japan, we have.
\begin{equation}
\begin{aligned}
a&= 230\\
r&= 23\% = 0.23\\
b&=1-r = 0.77\\
\end{aligned}
\end{equation}
A model of the Japan solar PV market can be written as:
\begin{equation}
\begin{aligned}
J(t)&=a\cdot b^t\\
&=230\cdot (0.77)^t
\end{aligned}
\end{equation}
A) Set $t= 8$ to correspond for the year for 2015 since 2007.
\begin{equation}
\begin{aligned}
W(8)&=2826\cdot (1.62)^8\\
&=134057.86
\end{aligned}
\end{equation}
\begin{equation}
\begin{aligned}
J(8)&=230\cdot (0.77)^8\\
&=28.42
\end{aligned}
\end{equation}
The world PV market in 2015 was about $134,057.86\ Mw$ and that of Japan was about $28.42\ Mw$.
B)
\begin{equation}
\begin{aligned}
\frac{J}{W}&=\frac{230}{2826}\\
&=8.14\%
\end{aligned}
\end{equation} \begin{equation}
\begin{aligned}
\frac{J}{W}&=\frac{28.42}{134057.86}\\
&=0.021\%
\end{aligned}
\end{equation}
The percentages are $8.14\%$ 2007 and $0.021\%$ 2015.
