# Approximation of binomial to normal

The proportion of defective telephones manufactured on Mondays is 0.3. If a sample of 20 telephones is selected, what is the probability that 5 of the phones in the sample are defective? Use the normal distribution to approximate the binomial. Since this is a continuous distribution approximating a discrete distribution, use X values of 4.5 and 5.5. Show your work.

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μ = np and σ = √ npq

https://brainmass.com/statistics/normal-distribution/approximation-binomial-normal-80376

#### Solution Preview

Using normal approximation we have

μ = np = 20*0.3 = 6

σ = √ npq = ...

#### Solution Summary

The approximation of binomial to normal functions are determined.

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