document.write( "Question 323240: supposed to use Central Limit Theorem to figure out...please help...i have a ti84 calculator..not sure how to get started
\n" ); document.write( "The average weight of a bag of Hershey's Miniatures is 368 grams with a standard deviation of 38 grams. You buy 20 bags and find the average weight of the 20 bags is 352 grams.
\n" ); document.write( "A. Assuming the weight listed on the bag is correct, what is the probability of the mean of the sample being less than 352 grams?
\n" ); document.write( "B. What do you think of Hershey's claim?
\n" ); document.write( "C. Would it be unusual to have an individual bag weigh less than 352? \n" ); document.write( "
Algebra.Com's Answer #231400 by Edwin McCravy(20063)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Draw a normal curve on the x-axis marking the middle point\r\n" );
document.write( "as the mean 352.  Then mark off units right and left by adding the\r\n" );
document.write( "standard deviation 20 to the mean to mark points to the right and \r\n" );
document.write( "subtracting 20 from the mean to get points on the left side. \r\n" );
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document.write( "We'll draw a green \"cut-off\" line at 352: \r\n" );
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document.write( "We want the area to the left of the green line above.  We can use the\r\n" );
document.write( "z-distribution even with a sample size less than 30, because we are\r\n" );
document.write( "assuming that we know sigma.  We also must assume that the distribution\r\n" );
document.write( "is known to be normal, for if it is not we cannot do the problem at all with\r\n" );
document.write( "that small a sample.  That's because the central limit theorem only holds for\r\n" );
document.write( "sample sizes of 30 or more when the population is not known to be normally\r\n" );
document.write( "distributed.  So your problem should have stated that the distribution\r\n" );
document.write( "is known to be normal for otherwise, and for the problem to be doable,\r\n" );
document.write( "you would need a sample size of 30 or more.  I will assume the population\r\n" );
document.write( "is known to be normal.\r\n" );
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document.write( "Press ON\r\n" );
document.write( "Press CLEAR\r\n" );
document.write( "Press 2ND\r\n" );
document.write( "Press VARS\r\n" );
document.write( "Press 2\r\n" );
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document.write( "you should see  \" normalcdf(  \" with the flashing cursor after that) \r\n" );
document.write( "After that type \r\n" );
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document.write( "-99999999,352,368,38/Ö(20))\r\n" );
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document.write( "That's a negative sign, (-), not a minus sign! \r\n" );
document.write( "The comma key is just above the 7 key.\r\n" );
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document.write( "You should see this on your screen:\r\n" );
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document.write( "normalcdf(-99999\r\n" );
document.write( "999,352,368,38/Ö\r\n" );
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document.write( "Press ENTER   \r\n" );
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document.write( "you see .029849806\r\n" );
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document.write( "That's about .03 or 3%, so only 3% of the time\r\n" );
document.write( "would a sample size be that low, so we would rightfully\r\n" );
document.write( "suspect that the claim that the mean is 368 is incorrect.\r\n" );
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document.write( "Edwin
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