Answer:
23,900 units
Step-by-step explanation:
The number of units expected to be manufactured in March must equal the total number of units sold in all territories (6,400 + 9,400 + 7,100), added to the difference between the desired inventory at the end of the month (19,400 units) and the estimated inventory at the beginning of the month (18,400 units).
The expected number (n) is:

The number of units expected to be manufactured in March is 23,900.