Question 1192596
Exactly 15 would be 25C15*0.75^15*0.25^10 using binomial formula.
=0.0417
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Exactly 20 would be 25C20*0.75^20*0.25^5=0.1645
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z=(x-mean)sd,
>2000/2400 or 0.83
probability is 0.2033 that z>0.83
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probability is for z<-5/12  (-1000/2400)
that is 0.3385