The Cost of Good Sold is $36,000 lower than it should have been and the net income is $36,000 higher than it should have been.
There are two formulas that are important to know for this question. The first is Beg. Inventory + Purchases - Ending Inventory = COGS. The second formula is Sales - Cost of Good Sold = Gross Profit.
If you reported a higher ending inventory it is going to result in a lower value for Cost of Good Sold. In this case the company had too high of an ending inventory by $36,000, which mean that the COGS is $36,000 lower than actual.
When you have a COGS that is lower than it should be you are going to have a gross profit which is overstated. The Income is overstated by $36,000.