# Math Help - finding the value of x

1. ## finding the value of x

Hello, how to I find the value of x? The problem I'm doing has a graph of 160< x < 168 with the mean of 168 and the standard deviation of 5.54. I'm having a hard time with finding what x should be. I'm supposed to assume the variable x is normally distributed. Thank you.

2. It would appear you have two x values. I don't know what you mean by finding the x values.

I am guessing you need to find the area under the standard normal curve.

Just use the table and subtract the two values.

$z=\frac{x-{\mu}}{\sigma}=\frac{168-168}{5.54}=0$

$\frac{160-168}{5.54}=-1.444...$

From the table:

z=0 corresponds to the mean and it's value is 0.5

z=-1.444... corresponds to 0.07436...

0.5-0.07436=0.425

Here's a graph of your region. I assume this is what you're meaning.