Answer
$310.1
Work Step by Step
We are given $P=6800, i=\frac{0.12}{12}=0.01, n=24$
the formula is $P=R[\frac{1-(1+i)^{-n}}{i}]$
so $\rightarrow R=\frac{P}{[\frac{1-(1+i)^{-n}}{i}]}$
$=\frac{6800}{[\frac{1-(1+0.01)^{-24}}{0.01}]}\approx \$310.1$