Find the area under Standard Normal Curve to the left of Z
The normal distribution is a continuous probability distribution. The total area under the standard normal curve is always 1. The normal distribution looks like a bellshaped curve.
In this article, we will discuss a stepbystep guide on finding the area under the standard normal curve to the left of the z score.
The area under the Standard Normal Curve to the left of z
Steps to find the area under the standard normal curve to the left of z

Step 1: Choose between a negative ztable or a positive ztable corresponding to the given zscore.

Step 2: Check the area value for the given z in the ztable.

Step 3: Look at the first two digits of the zscore on the left side column (yaxis) of the ztable and then the remaining number on the xaxis on the topmost row.

Step 4:The intersection of the two will be the required area.

Step 5: Multiply it by 100 to calculate the percentage of area.
Let’s understand find the area under the standard normal curve to the left of z using an example.
ZScore Tip: Read more on how to calculate the zscore!
How do you find the area to the left of z = 1.55?
To find the area to the left of the given z follows the below steps:

Step 1: Choose a positive ztable as the given zscore (i.e 1.55) is positive.

Step 2: Check the area value for the given z in the ztable.

Step 3: Look at the first two digits (1.5) of the zscore on the left side column (yaxis) of the ztable and then the remaining number (0.05) on the xaxis on the topmost row.

Step 4:The intersection of the two is 0.9394 (highlighted in red).

Step 5: Multiply it by 100 to calculate the percentage of area.
area to the left = 0.9394*100 = 93.94%
 Result: The area to the left of z is 93.94% of the normal standard curve.
Conclusion
I hope the above article to find the area under the standard normal curve to the left of z using step by step guide is helpful to you.
You can find more topics about ZScore and how to calculate z score given the area on the ZscoreGeek home page.