Answer and Explanation:
The computation is shown below:
a) Assets turnover 
 Particulars YRC UNP CH 
Sales $4,697,500 $19,941,000 $13,144,413 
Average total assets $1,824,700 $55,159,000 $3,436,058 
Assets turnover 2.6 0.4 3.8 
b. The ratio of sales to assets calculated the sales dollars i.e. earned for each assets. The more the no of sales dollars the more the firm would be considered efficient