Three Identical Units of Merchandise Were Purchased During March, as Shown

Three identical units of merchandise were purchased during March, as shown:? $$\begin{array} { | c | l | c | r | } \hline &{ \textbf { Steele Plate } } & \textbf { Units } &{ \textbf { Cost } } \\\hline \text { Mar. 3 } & \text { Purchase } & 1 & \$ 830 \\\hline 10 & \text { Purchase } & 1 & 840 \\\hline 19 & \text { Purchase } & \underline { 1 } & \underline { 880 } \\\hline \text { Total } & & 3 & \textbf{\underline {\$ 2.550}} \\\hline\end{array}$$ ?Assume that one unit is sold on March 23 for $1,125. Determine the gross profit for March and ending inventory on March 31 using
(a) FIFO,
(b) LIFO, and
(c) average cost methods.