It especially makes investing in ETFs geared to a particular market segment or average less rewarding.

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And while Ortiz has been a Yankees nemesis almost since the day he joined the Red Sox in 2003, the surprising Iglesias has quickly become a particular pest to them this season with a .545 average in 22 at-bats.

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That tells you how a particular weather option should play out, on average.

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Some types of expenditure are estimated by reference to an average level of spending for a particular household type, using data from the Family Expenditure and Food Survey.

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Last year we looked at the 20 largest actively managed international and U.S. mutual fund portfolios, and the median number of stock holdings per portfolio was 115, or less than a 1% stake on average in any particular holding.

FORBES

Athlete brands are calculated by subtracting the average endorsement income of the top 10 athletes in a particular sport from what the athlete earns from endorsements.

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What's more, while the average Champagne grape loses its identity in a huge blending vat, grower Champagnes reflect the character of a particular site, or village.

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