The following ratios are computed based on the financial data of SuperMart, a large company that operates in food and staple retailing.

Ratio	2019	2020
Operating profit margin	4.54%	5.06%
ROA	7.96%	5.74%
Current ratio	1.12:1	1.23:1
Quick ratio	0.28:1	0.23:1
Average Inventory turnover period	36.51 days	35.26 days
Average Accounts Receivable settlement period	0.69 days	0.73 days
Average Accounts Payable settlement period	40.62 days	43.04 days

Required:

1. Interpret the change in the operating profit margin in 2019-2020. Consider carefully what aspect of the operating had changed in the period.
2. Interpret the change in the ROA in 2019-2020. Consider carefully what aspect of the operating had changed in the period.
3. The operating profit margin and ROA showed opposite trends in 2019-2020. Provide two possible explanations to account for the disparity.
4. The company did not have a liquidity issue despite a low quick ratio in both years, why do you think this might be the case.