If a set of sample measurements has a mean of 100, a normal distribution, a standard deviation of 2, and control limits of 94 and 106, what percentage of the samples are expected to be between 94 and 106? Explain your answer.

Respuesta :

Answer: 99.73%

Step-by-step explanation:

Given : Mean : [tex]\mu=100[/tex]

Standard deviation : [tex]\sigma=2[/tex]

Let X be the random variable that represents the data values.

Formula for Z-score :  [tex]z=\dfrac{X-\mu}{\sigma}[/tex]

For x=94, we have

[tex]z=\dfrac{94-100}{2}=-3[/tex]

For x=106, we have

[tex]z=\dfrac{106-100}{2}=3[/tex]

The probability that the samples are between 94 and 106:-

[tex]P(-3<x<3)=1-2P(z<-3)\\\\=1-2(0.0013499)=0.9973002\approx0.9973=99.73\%[/tex]

Hence, the percent of the samples are expected to be between 94 and 106 = 99.73%