document.write( "Question 549289: The weight of a new-born baby follows a normal distribution with mean 3.44 kg
\n" ); document.write( " and standard deviation 1.31 kg. The probability of the average weight of n new-
\n" ); document.write( " born babies being greater than 3.13 kg is 0.937. Find the value of n \n" ); document.write( "
Algebra.Com's Answer #357594 by stanbon(75887)\"\" \"About 
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The weight of a new-born baby follows a normal distribution with mean 3.44 kg
\n" ); document.write( "and standard deviation 1.31 kg. The probability of the average weight of n new-
\n" ); document.write( "born babies being greater than 3.13 kg is 0.937. Find the value of n
\n" ); document.write( "------
\n" ); document.write( "x-bar = 3.13
\n" ); document.write( "AND
\n" ); document.write( "z(3.13) = (3.13-3.44)/(1.31/sqrt(n)
\n" ); document.write( "Find the z-score with a left-tail of 1-0.937 = 0.0630:
\n" ); document.write( "invNorm(0.0630) = -1.5301
\n" ); document.write( "---
\n" ); document.write( "So (3.13-3.44)/[1.31/sqrt(n)] = -1.5301
\n" ); document.write( "-0.31/(1.31/sqrt(n)) = -1.5301
\n" ); document.write( "1.31/sqrt(n) = -0.31/-1.5301 = 0.2026
\n" ); document.write( "sqrt(n) = 1.31/0.2026 = 6.4658
\n" ); document.write( "n = 41.8 rounding up to 49
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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