Suppose that people's heights (in centimeters) are normally distributed, with a mean of 170 and a standard deviation of 5. We find the heights of 90 people. (Round answer to nearest whole number.)

how many would you expect to be 170 & 180 cm tall?

For height=170cm, z1=(170-170)/5=0

For height=180cm, z2=(180-170)/5=2

According to standard normal distribution table, the probability that z<0 is 0.5, the probability that z<2 is 0.9772

So the probability between z=0 and z=2 is .9772-0.5=0.4772

90x0.4772~43

So we would expect 43 people to be 170 & 180 cm tall.

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