document.write( "Question 261695: A company specialises in packing of washing powder for a national chain of supermarkets.The machine used to pack the washing powder is calibrated to pack a mean of 510g.However,the packing machine is 100% reliable and there is some variation in the mean.The variability as measured by the standrd deviation is 2.5g.It is also known that the weight packed by the machine follows a normal distribution.The supermarket chain has recently been complaining because they think that too many washing powder boxes are either underweight or overweight.\r
\n" ); document.write( "\n" ); document.write( "a)What is the percentage of the bags filled by the machine will weigh less that 507.5g?
\n" ); document.write( "b)What is the probability that a bag filled by the machine weighs less than 512g?
\n" ); document.write( "c)What percentage of the bags will weigh between 512 and 515g?
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Algebra.Com's Answer #192800 by stanbon(75887)\"\" \"About 
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A company specialises in packing of washing powder for a national chain of supermarkets.
\n" ); document.write( "The machine used to pack the washing powder is calibrated to pack a mean of 510g.
\n" ); document.write( "However,the packing machine is not 100% reliable and there is some variation in the mean.The variability as measured by the standrd deviation is 2.5g.
\n" ); document.write( "It is also known that the weight packed by the machine follows a normal distribution.The supermarket chain has recently been complaining because they think that too many washing powder boxes are either underweight or overweight.
\n" ); document.write( "a)What is the percentage of the bags filled by the machine will weigh less that 507.5g?
\n" ); document.write( "z(507.5) = (507.5-510)/2.5 = -1
\n" ); document.write( "P(x<507.5) = P(z<-1) = 0.1587 = 15.87%
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\n" ); document.write( "b)What is the probability that a bag filled by the machine weighs less than 512g?
\n" ); document.write( "z(512) = (512-510)/2.5 = 0.8
\n" ); document.write( "P(x<512) = P(z<0.8) = 0.7881 = 78.81%
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\n" ); document.write( "c)What percentage of the bags will weigh between 512 and 515g?
\n" ); document.write( "Find the z-scores then find the % of population between those
\n" ); document.write( "scores. I get 18.91% using a TI calculator.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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