Question 627910
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Hi,
MEAN = 230 with a standard deviation of 22
 .10  &#8658; Z = -1.2816 = (X-230)/22  OR X = {{{22*-1.2816 + 230 = 202}}}
 .90  &#8658; Z = 1.2816 = (X-230)/22  OR X = {{{22*1.2816 + 230 = 258}}}
What number of fish per trap would he expect in the interval symmetrical about the mean 
where 80% of the numbers would be found.  202 to 258 fish per trap  
{{{drawing(400,200,-5,5,-.5,1.5, graph(400,200,-5,5,-.5,1.5, exp(-x^2/2)), green(line( 1.2816,0, 1.2816,exp(- 1.2816^2/2)),line(-1.2816,0,-1.2816,exp(-1.2816^2/2))),locate(4.8,-.01,z),locate(4.8,.2,z))}}}