document.write( "Question 1079088: Let x be a continuous random variable that has a normal distribution with μ=87 and σ=12. Assuming nN≤0.05, find the probability that the sample mean, x¯, for a random sample of 20 taken from this population will be between 83.9 and 91.5. \n" ); document.write( "
Algebra.Com's Answer #693482 by stanbon(75887)\"\" \"About 
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Let x be a continuous random variable that has a normal distribution with μ=87 and σ=12. Assuming nN≤0.05, find the probability that the sample mean, x¯, for a random sample of 20 taken from this population will be between 83.9 and 91.5.
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\n" ); document.write( "z(83.9) = (83.9-87)/[12/sqrt(20)] = -1.1553
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\n" ); document.write( "z(91.5) = (91.5-87)/[12/sqrt(20)] = 1.6771
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\n" ); document.write( "P(83.9<= x-bar <=91.5) = P(-1.1553<= z <= 1.6771) = 0.8293
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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