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

find z score for area using TI-NSpire

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.

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

Find z score for area to right using TI-NSpire

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.

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.