Question 938371
Ho: p =.79 (claim)
Ha: p > .79
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Sample: p = 162/200 = .81
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test stat {{{z =blue (x - mu)/sqrt(blue(p(1-p)/n))}}} :  z = .02/sqrt[0.79*0.21/200) = .6944
P(z > .6944) = normalcdf(.6944,100)
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Test at the 5% level of significance
normalcdf(.6944,100) > .05
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Test results support the claim that p = .79
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For the normal distribution: Below:  z = 0, z = ± 1, z= ±2 , z= ±3 are plotted.  
Note: z = 0 (x value: the mean) 50% of the area under the curve is to the left and 50%  to the right
{{{drawing(400,200,-5,5,-.5,1.5, graph(400,200,-5,5,-.5,1.5, exp(-x^2/2)), green(line(1,0,1,exp(-1^2/2)),line(-1,0,-1,exp(-1^2/2))),green(line(2,0,2,exp(-2^2/2)),line(-2,0,-2,exp(-2^2/2))),green(line(3,0,3,exp(-3^2/2)),line(-3,0,-3,exp(-3^2/2))),green(line( 0,0, 0,exp(0^2/2))),locate(4.8,-.01,z),locate(4.8,.2,z))}}}