How to calculate percentages on a TI-89 for a normal probability distribution?

[sublime]

I have a ti-89, does anyone know how to calculate percentages of teh normal model on it? I am not sure what the function is, and using the table in the back of my book is a pain. The problem's I mean are, for example-
given N(80,5) what percentage of the data is above 92 given the information fits a normal probabilty distribution. note i don't have the 89 titanium so i may not have certain programs. Thank you

 

[0rthodontist]

I don't see a function for that immediately. You can always just ask it to numerically evaluate the integral of the normal distribution from whatever value you want to some high value like 100.

 

[tacman]

Calculating percentages on a TI-89 for a normal probability distribution is a straightforward process. First, you will need to access the "DISTR" menu by pressing the "2nd" button followed by the "VARS" button. This will bring up a list of different distributions, including the normal distribution (which is denoted as "normalcdf").

To calculate the percentage of data above 92 in a normal distribution with a mean of 80 and standard deviation of 5, you can use the following steps:

1. Enter the values for the mean and standard deviation into the calculator by typing "80" followed by the "2nd" button and then the "comma" button (which represents the decimal point), and then "5".

2. Next, type in the upper limit of the range you want to calculate the percentage for, which in this case is 92. So you would type "92" followed by the "comma" button.

3. Now, type in a very large number for the lower limit, such as "9999" followed by the "comma" button.

4. Finally, press the "ENTER" button to calculate the percentage. The answer should be displayed as a decimal, so if you want to convert it to a percentage, simply multiply it by 100.

In this example, the percentage of data above 92 in a normal distribution with a mean of 80 and standard deviation of 5 is approximately 6.68%. You can also use this method to calculate percentages for other ranges or values in a normal distribution. I hope this helps!