Question

What is the probability that the mean random sample of 9 students will be less than 88? Given: = 4 ̅ = 88 = 86 n=9

Answer 1

$$P(X<88)=P(Z<\dfrac{88-\mu}{\sigma/\sqrt{n}})$$

$$=P(Z<\dfrac{88-86}{4/\sqrt{9}})=P(Z<1.5)$$

$$\approx0.9332$$