The height of the students at a particular university is normally distributed with a mean of 63 inches and a standard deviation of 3 inches. There are 5000 students at this university. How many students have a height between 60 to 66 inches?
Let X be a random variable represents the height of the students, then X ~ N(63, 3) = 63 + 3N(0,1)
"P(60<X<66)=P(60<63+3N(0,1)<66)=P(-1<N(0,1)<1)=P(N(0,1)<1)-P(N(0,1)<-1)=0.84134-0.15866=0.68268"
Among the 5000 students there will be approximately "5000*0.68268=3413.4" students with height between 60 and 66 inches
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