document.write( "Question 1177946: Replacement times for TV sets has a mean of 8.2 years and a standard deviation of 1.1 years.\r
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\n" ); document.write( "\n" ); document.write( "a. What is the probability that a randomly selected TV set will have replacement time in less than 8 years? Give your answer to four decimal places.\r
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\n" ); document.write( "\n" ); document.write( "b. What is the probability that 40 randomly selected TV sets will have a mean replacement time that is less than 8 years? Give your answer to four decimal places.\r
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Algebra.Com's Answer #807110 by ewatrrr(24785)\"\" \"About 
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document.write( "Hi\r\n" );
document.write( "Normal distribution:    μ = 8.2years   σ = 1.1years \r\n" );
document.write( "Using TI or similarly an inexpensive calculator like a Casio fx-115 ES plus\r\n" );
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document.write( "a. P(x < 8) = normalcdf(-9999, 8,8.2,1.1) = 0.4279\r\n" );
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document.write( "b. P( x̄ < 8)= normalcdf(-9999, 8,8.2,1.1/√40) = .125\r\n" );
document.write( "or\r\n" );
document.write( "z = (8-8.2)/1.1/sqrt(40) = -1.1499 \r\n" );
document.write( "P( z ≤ -1.1499) = .125\r\n" );
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document.write( "Wish You the Best in your Studies.\r\n" );
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