document.write( "Question 477232: Find the range, standard deviation, and variance for the following sample data:
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document.write( "33, 55, 29, 40, 43, 8, 90, 61, 41, 17, 80, 56, 17, 59, 21, 78 \r
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document.write( "Thank you \r
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Algebra.Com's Answer #327145 by jim_thompson5910(35256) ![]() You can put this solution on YOUR website! Range = Largest Value - Smallest Value\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Range = 90 - 8\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Range = 82\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "=========================================================================\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Finding the sample variance and sample standard deviation:\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "First, we need to find the sample mean xbar\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "xbar = (33+55+29+40+43+8+90+61+41+17+80+56+17+59+21+78)/16 = 728/16 = 45.5 \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the sample mean is xbar = 45.5 \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now subtract the sample mean from EVERY data value:\r \n" ); document.write( "\n" ); document.write( "33-45.5 = -12.5 \n" ); document.write( "55-45.5 = 9.5 \n" ); document.write( "29-45.5 = -16.5 \n" ); document.write( "40-45.5 = -5.5 \n" ); document.write( "43-45.5 = -2.5 \n" ); document.write( "8-45.5 = -37.5 \n" ); document.write( "90-45.5 = 44.5 \n" ); document.write( "61-45.5 = 15.5 \n" ); document.write( "41-45.5 = -4.5 \n" ); document.write( "17-45.5 = -28.5 \n" ); document.write( "80-45.5 = 34.5 \n" ); document.write( "56-45.5 = 10.5 \n" ); document.write( "17-45.5 = -28.5 \n" ); document.write( "59-45.5 = 13.5 \n" ); document.write( "21-45.5 = -24.5 \n" ); document.write( "78-45.5 = 32.5\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the differences are: -12.5, 9.5, -16.5, -5.5, -2.5, -37.5, 44.5, 15.5, -4.5, -28.5, 34.5, 10.5, -28.5, 13.5, -24.5, 32.5 \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now square each difference:\r \n" ); document.write( "\n" ); document.write( "(-12.5)^2 = 156.25 \n" ); document.write( "(9.5)^2 = 90.25 \n" ); document.write( "(-16.5)^2 = 272.25 \n" ); document.write( "(-5.5)^2 = 30.25 \n" ); document.write( "(-2.5)^2 = 6.25 \n" ); document.write( "(-37.5)^2 = 1406.25 \n" ); document.write( "(44.5)^2 = 1980.25 \n" ); document.write( "(15.5)^2 = 240.25 \n" ); document.write( "(-4.5)^2 = 20.25 \n" ); document.write( "(-28.5)^2 = 812.25 \n" ); document.write( "(34.5)^2 = 1190.25 \n" ); document.write( "(10.5)^2 = 110.25 \n" ); document.write( "(-28.5)^2 = 812.25 \n" ); document.write( "(13.5)^2 = 182.25 \n" ); document.write( "(-24.5)^2 = 600.25 \n" ); document.write( "(32.5)^2 = 1056.25\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now add up each square:\r \n" ); document.write( "\n" ); document.write( "156.25+90.25+272.25+30.25+6.25+1406.25+1980.25+240.25+20.25+812.25+1190.25+110.25+812.25+182.25+600.25+1056.25 = 8966\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now divide that sum by n-1 = 16-1 = 15 to get 8966/15 = 597.733333333333\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the sample variance is 597.733333333333\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Finally, take the square root of 597.733333333333 to get 24.448585507823\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the sample standard deviation is 24.448585507823\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |