document.write( "Question 279663: Procter & Gamble reported that an American family of four washes an average of 1 ton (2000 lbs) of clothes each year. If the standard deviation is 187.5 lb, find the probability that the mean of a randomly selected sample of 50 families of four will be between 1980 and 1990 lbs. \n" ); document.write( "
Algebra.Com's Answer #203322 by stanbon(75887)\"\" \"About 
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Procter & Gamble reported that an American family of four washes an average of 1 ton (2000 lbs) of clothes each year. If the standard deviation is 187.5 lb, find the probability that the mean of a randomly selected sample of 50 families of four will be between 1980 and 1990 lbs.
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\n" ); document.write( "t(1990) = (1990-2000)/[187.5/sqrt(50)] = -0.3771
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\n" ); document.write( "t(1989) = (1980-2000)/[187.5/sqrt(50)] = -0.7542
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\n" ); document.write( "P(1980< x < 1990) = P(-0.7542< t < -0.3771)
\n" ); document.write( "= tcdf(-0.7542,-0.2771,49) = 0.1267
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.\r
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