Question

Consider the probability that more than 99 out of 157 software users will not call technical support. Assume the probability that a given software user will not call technical support is 56%. Approximate the probability using the normal distribution

Answer 1

Answer:

$P(x>99)= 0.468$

Step-by-step explanation:

From the question we are told that:

Sample size 157

Sample mean

$\=x =np$

$\=x =157*0.56$

$\=x = 87.92$

Generally the equation for Standard deviation is mathematically given by

$\sigma=\sqrt{npq}$

$\sigma=\sqrt{157*0.56*0.44}$

$\sigma =6.22$

Therefore

$P(x>99)=P(z>(\frac{99.5-87.92)}{6.22})$

$P(x>99)=P(z>1.86)$

$P(x>99)= 0.468$