The Normal Cumulative Distribution Function normalcdf() is used to find percentiles from the z score on the TI84 calculator.
normalcdf
(lower bound, zscore, μ, σ)
where:
 lower bound: lower bound for the given zscore. We use infinity as a lower bound.
 Zscore: given zscore
 μ: population mean
 σ: population standard deviation
How to find percentile from z score using TI 84
The following steps will guide us on how to calculate the Percentiles from ZScore using TI84 Calculator:

Step 1: Press “2nd” and then press “VARS”.This will take you to a DISTR screen.

Step 2: Now, select “normalcdf“ i.e. 2nd option, and then press “ENTER” to open the normalcdf wizard screen.

Step 3: Enter the lower bound, zscore followed by 0 for mean and 1 for standard deviation.
For example, to find the Percentiles for a zscore of 1.2 on the TI84 calculator,
type 1000,1.2,0,1. Here the lower bound is infinity, so type 1000.
Always use large numbers to represent infinity, like 1000 in this case.
 Step 4: Type a closing parenthesis “)” and then press ENTER.
The TI84 Plus will calculate the percentile associated with the given zscore.
Let’s discuss a few examples to find percentiles from the Zscore on TI84.
How to find the Percentile of Negative Zscore on TI84?
Let’s consider an example to find the percentile from z score 1.58 on the TI84 calculator
The following steps will guide us on how to calculate the Percentiles from ZScore = 1.58 Using the TI84 Calculator
Let’s draw the normal distribution curve for the given zscore = 1.58

Step 1: Press “2nd” and then press “VARS”.This will take you to a DISTR screen.

Step 2: Select “normalcdf“ i.e. 2nd option, and press “ENTER” to bring up the normalcdf wizard screen.

Step 3: Enter the lower bound, zscore followed by 0 for mean and 1 for standard deviation. In this case, type 1000,1.58,0,1.
Note: Here the lower bound is infinity, so type 1000.
 Step 4: Type a closing parenthesis “)” and then press ENTER.
The TI84 Plus will calculate the percentile associated with the given 1.58 zscore.
The resultant percentile for the given zscore = 1.58 is 0.0571.
Conclusion: It concludes that 5.71% of the data values in the standard normal distribution lies below the zscore of 1.58.
How to find the Percentile of Positive Zscore on TI84?
Let’s consider an example to find the percentile from z score 0.31 on the TI84 calculator.
The following steps will guide how to calculate the Percentiles from ZScore = 0.31 on TI84 Calculator:

Step 1: Press “2nd” and then press “VARS”.This will take you to a DISTR screen.

Step 2: Select “normalcdf“ i.e. 2nd option, and then press “ENTER” to bring up the normalcdf wizard screen.

Step 3: Enter the lower bound, zscore followed by 0 for mean and 1 for standard deviation. In this case, type 1000,0.31,0,1.
Note: Here the lower bound is infinity, so type 1000.
 Step 4: Type a closing parenthesis “)” and then press ENTER.
The TI84 Plus will calculate the percentile associated with the given 0.31 zscore.
The resultant percentile for the given zscore = 0.31 is 0.6217.
Conclusion: It concludes that 62.17% of the data values in the standard normal distribution lies below the zscore of 0.31.
Conclusion
I hope the above article to find percentile from z score on the TI84 calculator is useful to you.
In the above article, we have learned how to find the percentile from a negative z score on a TI84 calculator and find the percentile from a positive z score on the TI84 calculator.
Normal Cumulative Distribution function normalcdf() function is used to find the percentile for a given z score on the TI84 calculator.