The Inverse Normal Probability Distribution Function invNorm() is used to find the z score on TI-NSpire.
invNorm(area, μ, σ)
where:
- area: the given area to the left.
- μ: population mean
- σ: population standard deviation
Note: Finding the Z-score indicates that the given distribution is a standard normal distribution with a mean of 0 and a standard deviation of 1.
In this blog post, we will discuss with step by step guide on how to find the z score on TI-NSpire and examples.
How to use invNorm to find z score on TI NSpire
The following steps will guide us on using the invnorm function, and how to calculate the Z-Score on TI-NSpire Calculator:
Step 1: Press the “menu” button and select Statistics i.e. 6th option.
Step 2: Select “Distribution” i.e 5th option.
Step 3: Now, select “Inverse Normal function” (invNorm) i.e 3rd option, and it brings up the inverse Normal wizard screen.
Step 4: Enter the given area in the area column followed by 0 for mean and 1 for standard deviation. For example, to find the z-score associated with the 0.145 area, type 0.145,0,1.
The TI-nspire will calculate the z-score associated with the given area.
Let’s discuss a few examples to find the z score for the given area on TI NSpire
Find Z-Score corresponding to the area 0.8665 Using TI-nspire
Let’s draw the normal distribution curve for area = 0.8665

The following steps will guide how to calculate the z score for the area 0.8665 on TI-nspire Calculator:
Step 1: Press the “menu” button and select Statistics i.e. 6th option.
Step 2: Select “Distribution” i.e 5th option.
Step 3: Now, select “Inverse Normal function” i.e 3rd option, and it brings up the inverse Normal wizard screen.
Step 4: Enter the given area 0.8665 in the area column followed by 0 for mean and 1 for standard deviation.
The resultant z-score for the given area is 1.1.
Conclusion: The Z-score associated with the 0.8665 area in the normal standard distribution is 1.1.
Cool Tip: Read more on how to calculate the z score on TI-84 plus!
Find Z Score for the area to the right is 0.3783 on TI-nspire
Let’s draw the normal distribution curve for the area to the right = 0.3783

The following steps will guide how to calculate the z score corresponding to the area to the right is 0.3783 on TI-nspire Calculator:
Step 1: Find the area to the left in order to calculate the z score.
area to the left = 1- area to the right
area to the left = 1 – 0.3783
area to the left = 0.6217.
Step 2: Press the “menu” button and select Statistics i.e. 6th option.
Step 3: Select “Distribution” i.e 5th option.
Step 4: Now, select “Inverse Normal function” i.e 3rd option, and it brings up the inverse Normal wizard screen.
Step 5: Enter the given area 0.6217 in the area column followed by 0 for mean and 1 for standard deviation.
The resultant z-score for the given area is 0.31.
Conclusion: The Z-score associated with the 0.3783 area to the right in the normal standard distribution is 0.31.
Cool Tip: Read more on how to Calculate Z Score in Excel!
Conclusion
I hope the article on how to find the z score on the TI-nspire calculator is useful to you.
invNorm (Inverse normal distribution) function is used to calculate the z score from the given area on the TI-nspire calculator.
Cool Tip: Read more on how to use the z table chart and how to find the z score for the top 5th percentile of standard normal distribution.
You can find more topics about Z-Score and how to calculate z score given the area, read the z score table on the ZScoreGeek home page.