Four firms control the market for a particular good,resulting in an HHI of 6,650.Total industry sales are $1,750,and it is known that one firm has sales of $1,400 and another sales of $175.If each of the remaining two firms has the same sales,then we can conclude that the remaining two firms each have a market share of:

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The Herfindahl-Hirschman Index (HHI) is calculated by summing the squares of the market shares of all firms in the market. Given an HHI of 6,650, total industry sales of $1,750, one firm with sales of $1,400, and another with sales of $175, we can calculate the market shares of these firms: Firm 1's market share = $1,400 / $1,750 = 0.8 (or 80%), and Firm 2's market share = $175 / $1,750 = 0.1 (or 10%). The HHI is calculated as the sum of the squares of the market shares (expressed as whole numbers), so for these two firms, we have (0.8)^2 + (0.1)^2 = 0.64 + 0.01 = 0.65. The total HHI is 6,650, which is equivalent to 6,650 / 10,000 in terms of market shares, leaving 0.665 - 0.65 = 0.015 (or 1.5%) to be accounted for by the remaining two firms. If these two firms have equal shares, each would have 0.75% of the market, which as a decimal is 0.0075. To find the market share as a fraction, we divide 0.0075 by the total market share (1 or 100%), resulting in 0.05 or 5% for each of the remaining two firms.

Four Firms Control the Market for a Particular Good,resulting in an HHI