Question 1170807
z=(x-mean)/sd
z > (18000-16000)/800 or 2.5
that probability is 0.0062
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z (0.80)=0.8416
0.8416=(t-16000)/800
673.29=t-16000, will round to nearest integer
t=$16,673.
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z=(16200-16000)/800/sqrt(20)
-200*sqrt(20)/800=.
=1.118
That probability of z> than that value is 13.2%
The sd of the sampling distribution with n=20 has mean $16000 as before, but sd is 178.88