The questions is, when z=9, 3z = ? When you multiply 3*9, you get 27
Answer:
![z=\frac{x- \mu}{\sigma}](https://tex.z-dn.net/?f=%20z%3D%5Cfrac%7Bx-%20%5Cmu%7D%7B%5Csigma%7D)
And replacing we got:
![z=\frac{425-500}{75}= -1](https://tex.z-dn.net/?f=%20z%3D%5Cfrac%7B425-500%7D%7B75%7D%3D%20-1)
And we can calculate this probabilit using the normal standard distribution or excel and we got:
![P(z](https://tex.z-dn.net/?f=%20P%28z%3C-1%29%3D%200.159)
Step-by-step explanation:
If we define the random variable of interest "the amount spent by a family of four of food per month" and we know the following parameter:
![\mu = 500, \sigma = 75](https://tex.z-dn.net/?f=%20%5Cmu%20%3D%20500%2C%20%5Csigma%20%3D%2075)
And we want to find the following probability:
![P(X](https://tex.z-dn.net/?f=%20P%28X%3C425%29)
And we can use the z score formula given by:
![z=\frac{x- \mu}{\sigma}](https://tex.z-dn.net/?f=%20z%3D%5Cfrac%7Bx-%20%5Cmu%7D%7B%5Csigma%7D)
And replacing we got:
![z=\frac{425-500}{75}= -1](https://tex.z-dn.net/?f=%20z%3D%5Cfrac%7B425-500%7D%7B75%7D%3D%20-1)
And we can calculate this probabilit using the normal standard distribution or excel and we got:
![P(z](https://tex.z-dn.net/?f=%20P%28z%3C-1%29%3D%200.159)
Imagine you are a close friend/ relative to Shakespeare and write how you view him