When a P $=620$ W ideal $($lossless$)$ transformer is operated at full power with an rms input current of I$1=2\mathrm{.}8$ A$,$ it produces an rms output voltage of V$2=9\mathrm{.}4$ V$.$

$$ Part $($a$)$

What is the input voltage, in volts?

$$ Part $($b$)$

What is the output current, in amperes?

$$ Part $($c$)$

Calculate the ratio of primary to secondary turns.

$$ Part $($d$)$

Is this a step$-$up or a step$-$down transformer?