document.write( "Question 853759: In a normal distribution with a mean of 330 and a standard deviation of 60, find the upper and lower bounds that define the middle 80% of the distribution. \n" ); document.write( "

Algebra.Com's Answer #514269 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi,
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document.write( "mean of 330 and a standard deviation of 60,
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document.write( "80%, (1-.80)/2 = .10,    z = NORMSINV(.10) = -1.2816 ,  z = NORMSINV(.90) = 1.2816 
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document.write( " -1.2816 = (X -330)/60
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document.write( "60(-1.2816) + 330 = 253.104 or 254 to next whole number
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document.write( "60(1.2816) + 330 =  406.896 0r  407 rounded Up
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document.write( "254 & 407 define the upper and lower bounds of the middle 80% of the distribution \n" );
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