plese explain this question only on the given chart do not add chart on your side I again asking the question because my last answer was wrong which chegg send to me. so explain in good way on the bases on given chart.

7. This shows MEC's Gross Profit Ratio from 2015 to 2016 2017 2016 2015 Units sold 214,000 160,000 100,000 Gross profit from sales $84,300 $69,440 $46,400 Net sales $314,700 $248,000 $160,000 Gross profit ratio 26.8% 28.0% 29.0% a) Is the trend favourable or unfavourable? (1 Mark) b) What do you think is the explanation for your answer? (2 MARKS)