document.write( "Question 388626: 5) The weight of a newborn is a random variable X which has the standard normal distribution with the mean weight is 3 kg. The standard deviation  = 0.2 kg. The minimum weight of newborn is 1.5 kg.
\n" ); document.write( "a) Calculate the probability of newborn that has the weight within the interval 3kg to 3.4kg.
\n" ); document.write( "b) The newborn that has the weight less than 2.5kg is deprived of weight. Calculate the probability of newborn that deprived of weight.
\n" ); document.write( "c) The newborns in 10% of the smallest weight need look after careful. Calculate the maximum weight of newborn that need look after careful.
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #274992 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
The weight of a newborn is a random variable X which has the standard normal distribution with the mean weight is 3 kg. The standard deviation  = 0.2 kg. The minimum weight of newborn is 1.5 kg.
\n" ); document.write( "-------
\n" ); document.write( "a) Calculate the probability of newborn that has the weight within the interval 3kg to 3.4kg.
\n" ); document.write( "z(3 kg) 0
\n" ); document.write( "z(3.4 kb) = (3.4-3)/1.5 = 0.4/1.5 = 0.267
\n" ); document.write( "P(3< x < 3.4) = P(0< z < 0.267) = 0.1052
\n" ); document.write( "---------
\n" ); document.write( "b) The newborn that has the weight less than 2.5kg is deprived of weight. Calculate the probability of newborn that deprived of weight.
\n" ); document.write( "z(1.5) = (1.5-3)/1.5 = -1
\n" ); document.write( "z(2.5) = (2.5-3)/1.5 = -0.5/(1.5) = -1/3
\n" ); document.write( "P(1.5 < x < 2.5) = P(-1< z <-1/3) = 0.2108
\n" ); document.write( "============================
\n" ); document.write( "c) The newborns in 10% of the smallest weight need look after careful. Calculate the maximum weight of newborn that need look after careful.
\n" ); document.write( "-----
\n" ); document.write( "Find the z-value interval that has that 10% of the population.
\n" ); document.write( "Area below x = 1.5 = Area below z=-1 is 0.1587
\n" ); document.write( "The next 10% interval includes a left-tail of 0.2587
\n" ); document.write( "The z-value for that left tail is -0.6475
\n" ); document.write( "---
\n" ); document.write( "Max weight in that interval is : x = zs+u
\n" ); document.write( "x = -0.6475*1.5+3 = 2.0290 kg
\n" ); document.write( "========================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "
\n" );