Z Score for the top 5 percentile of a normal distribution is 1.645.
To find the top 5th percentile of a normal distribution, look at the z table. Check the probability closest to 0.05 in the z table. Sometimes the exact values do not exist, in that case, we will consider the best closest value.
In this blog post, we will discuss how to find the top 5 percentile of a standard normal distribution using the z table.
How to Calculate the percentile for zscore?
To find the nth of a normal distribution, follow the below steps:

Go to the Ztable and check the probability closest to the nth (convert it into decimal) in the values inside the table. Sometimes the exact values do not exist, in that case, we will consider the best closest value.

Find the zscore corresponding to the closest value i.e its corresponding row value and its corresponding column value.

Combine these numbers as row value + column value.
Conclusion: The nth percent of the normal distribution will be calculated zscore.
Let’s now find the top 5 percent of a normal distribution using the above steps.
Find the top 5 percentile of a normal distribution
The top 5% of the normal distribution indicates that only 5% of the data lies on the right of the normal standard curve.
So, the minimum percentile required left to the zscore is 95% i.e. (1005)%
As we know ztable tells us the probability of values less than the given zscore, we will check the 0.95 probability in the Ztable in order to calculate the top 5% of the normal distribution.
To find the zscore for the 95 percentile, we will follow the below steps:
Step 1: Go to the Ztable and check the probability closest to 0.95 in the values inside the table. Sometimes the exact values do not exist, in that case, we will consider the best closest value.
The closest value to 0.95 in the Ztable is 0.9495 and 0.9505
Step 2: Find the zscore corresponding to this value, its corresponding row value is 1.6 and its corresponding column value is either 0.04 or 0.05
Step 3: Combine these numbers to get the z score value for the 95th percentile as 1.645
Let’s understand how we calculate the 1.645 value, as we have two corresponding values 1.64 and 1.65 so we sum these numbers and divide by 2 as given below
1.6+0.04 = 1.64 and 1.6 + 0.05 = 1.65
= (1.64 + 1.65)/2
= 1.645
Result: The ZScore for the 95th percentile is 1.645 which means 95 percent of the data values of the normal distribution lies below the 1.645 zscore.
The top 5 percentile of a standard normal distribution is a 1.645 zscore.
Conclusion
I hope the above example to find the top 5 percentile of the normal distribution is helpful to you.