Answer:
 Year 2014 Year 2013
a) Inventory Turnover ratio 3.4 times and 3.1 times
b) Number of days' sales in inventory 107.3 days and 117.7 days
Step-by-step explanation:
As per the data given in the question,
As we know that
Inventory turnover ratio = Cost of goods sold ÷ Average inventory 
where, 
Average inventory 
= (Beginning inventory + ending inventory) ÷ 2
For Year 20Y4 :
Average inventory = ($359,160 + $516,840 ) ÷2
= $438,000
And, the cost of goods sold is $1,489,200
So, 
Inventory Turnover ratio 
= $1,489,200 ÷ $438,000
= 3.4 times
For Year 20Y3 :
Average inventory = ($251,120 + $359,160) ÷ 2
= $305,140
And, the cost of goods sold is $945,934
So, 
Inventory Turnover ratio 
= $945,934 ÷ $305,140
= 3.1 times
Now 
Number of days' sales in inventory = Number of days in a year ÷ Inventory Turnover ratio
For 20Y4 
= 365 days ÷ 3.4 
= 107.3 days
For 20Y3 
= 365 days ÷ 3.1 
= 117.7 days
Basically we applied the above formulas