To answer this question, we need to remember that the sum of the total area of a probability distribution is always 1.
First case: the area to the right of x
Then, if we have that the area to the left of x in a normal distribution is 0.272, the area to the right of x is:
[tex]A_{\text{rightx}}=1-0.272\Rightarrow A_{rightx}=0.728[/tex]If we sum both areas, we will get 1 as the total area of this probability distribution.
Second case: the area to the left of x
Now, if we have that
