The following information pertains to Mason Company for Year $2$:

Beginning inventory $140$ units @ $$40$

Units purchased $290$ units @ $$45$

Ending inventory consisted of $60$ units. Mason sold $370$ units at $$90$ each. All purchases and sales were made with cash. Operating expenses amounted to $$4,100.$

Required

Compute the gross margin for Mason Company using the following cost flow assumptions:

$(1)$ FIFO

$(2)$ LIFO and

$(3)$ weighted average

b$.$ What is the amount of net income using FIFO, LIFO, and weighted average? $($Ignore income tax considerations.$)$

c$.$ Determine the cash flow from operating activities, using each of the three cost flow assumptions listed in Requirement a$.$ Ignore the effect of income taxes.