Herbert has sold 90, 45, 103 and 68 appliances in the last four months, respectively. How many appliances will he need to sell this month to maintain an average of at least 77 sales per month

The sale this month = 79

Step-by-step explanation:

Let the amount he needs to sell this month = x

Note that number of entries = number of months = 5

To maintain an average sales of 77, the amount of sale in month 5 is determined as follows:

-6 is the correct option from the above given options