Question 1175051
z=(x-mean)/sd
so for a (140-124)/20 or z > 0.8
that probability is 0.2119 from the calculator 2ndVARS ENTER 2 normalcdf(.8,6) ENTER. The 6 is the std deviations to essentially 100%. Some use 1E99, 6 works, and it is easier. 7 would and 8 would, but 5 has some error.
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for b z=(x bar-mean(/sigma/sqrt(n), since std error of sample is sigma/sqrt(n).
This is z> (120-124)/20/sqrt(35) or > -4*sqrt(35)/20= -1.18 and that probability is 0.8810