Question 1178900
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Hi
n = 500
mean= np = .20*500 = 100
variance = 100*.80 = 80
sd = √80
Using TI or similarly an inexpensive calculator like an Casio fx-115 ES plus

P( 80 < x < 110) = normalcdf(80,110, 100, √80) = .8556

Wish You the Best in your Studies.
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