$19\mathrm{.}4$ LAB: Musical note frequencies

On a piano, a key has a frequency, say f$0.$ Each higher key $($black or white$)$ has a frequency of fo $*r^n,$ where $n$ is the distance $($number of keys$)$ from that key, and $r$ is $2^{(\frac{1}{12})}.$ Given an initial key frequency, output that frequency and the next $3$ higher key frequencies. Output each floating$-$point value with two digits after the decimal point using the following statement once before all other cout statements:

cout $$ fixed $$ setprecision$(2)$;

Include the units $("$Hz$")$ and a newline after each frequency, including the last.

Ex: If the input is:

$440\mathrm{.}0$

$($which is the A key near the middle of a piano keyboard$),$ the output is:

$440\mathrm{.}00Hz$

$466\mathrm{.}16Hz$

$493\mathrm{.}88Hz$

$523\mathrm{.}25Hz$

Note: To compute the next $3$ higher key frequencies, use one statement to compute $r=2^{(\frac{1}{12})}$ using the pow function $($remember to include the cmath library$).$ Then use that $r$ in subsequent statements that use the formula $f_n=f0**r^n$ with $n$ being $1,2$ and finally $3$