Suppose a ten firm industry has total sales of $35 million per year. The largest firm have sales of $10 million, the third largest firm has sales of $4 million, and the fourth largest firm has sales of $2 million. If fifth through tenth largest firms combined have annual sales of $12 million, the fourfirm concentration ratio for this industry is

0.66

Explanation:

the fourfirm concentration ratio is the sum of the concentration ratio of the four largest firms in the industry.

The sales of the second largest firm = $35 million - ( $10 million + $4 million+ $2 million + $12 million ) = $7 million

concentration ratio of firm 1 = $10 million / $35 million = 0.29

concentration ratio of firm 2  = $7 million / $35 million = 0.2

concentration ratio of firm 3 = $4 million / $35 million = 0.11

concentration ratio of firm 4 = $2 million / $35 million = 0.06

Adding the ratios together = 0.66

muslims control the north africa during the period of 1500 up

to 1800. they made a barrier to prevent further european exploration from

entering the africa from the north. however, the dutch ware still able to move

toward the interior with having south africa as one of the routes leading to

the east for trading with asia.