Answer:
a. Realized gross profit of $100,000.
Explanation:
In 2013, Rigsby Sales Co would realize:
Gross profit percentage = ($4,500,000 - $3,600,000) /4,500,000
Gross profit percentage = 0.20
Gross profit percentage = 20%
Gross profit to be realized is
Gross profit = Installment received * Percentage of gross profit
Gross profit = $500,000*20%
Gross profit = $100,000