In its first month of operations, McLanie Company made three purchases of merchandise in the following sequence: (1) 300 units at $6, (2) 400 units at $8, and (3) 500 units at $9. Assuming there are 200 units on hand at the end of the period.

the average unit cost:  $7.917

Explanation:

I think your question is missed of key information, allow me to add in and hope it will fit the original one.  

In its first month of operations, McLanie Company made three purchases of merchandise in the following sequence: (1) 300 units at $6, (2) 400 units at $8, and (3) 500 units at $9. Assuming there are 200 units on hand at the end of the period. Calculate average unit cost. (Round answers to 3 decimal places, e.g. 5.125.)

My

Given:

<=> Total units = 300 + 400 + 500 = 1200 units

<=> Total cost: 300*$6 + 400*$8 + 500*$9

= $1,800 + $3,200 + $4,500

= $9500

= Total cost / total units

=$9,500 ÷ 1,200 = $7.917

Hope it will find you well.

b. take periodic breaks and alternate between tasks.  

will increase work efficiency, and avoid health issues.