Answer:
Underpayment of estimated tax = $2,960
Step-by-step explanation:
Please consider the following equations:
100% of $15,960 = $15,960
90% of $18,000 = $16,200
whichever is lower. i.e $15,960
Underpayment of estimated tax = $15,960 - $13,000 = $2,960