Thursday, January 8, 2009

Classpad 330 and Normal Distribution

Normal distribution problems can be done quite simply on the Classpad 330, but the method seems a little weird.. perhaps I haven't found a menu yet, or completed an update.. but here's how I did it for the following problem.
"A packet of mince contains 500g of mince. Suppose the actual weight (x) of
these packets is normally distributed with a mean of 512 grams and a standard
deviation of 8 grams. What is the probability of picking a packet between 504
and 520g?"
Firstly open the main window and add the list editor from the toolbar.

Opening the list editor should make the Calc menu appear in the menubar at the top of the window.

Select Calc->Distribution. This will make a popup appear with some options

The Type dropdown needs to say Distribution.

The second dropdown should say Normal CD. After that is selected tap Next. A new dialog box will appear.

For our problem the lower bound is 504, the upper bound is 520, the standard deviation is 8 and the mean is 512. Tap Next when this has been entered. The answer will appear with a probability of 0.683

Tap the graph icon in the toolbar to view the distribution.

Here is a link to other CAS calculator posts.


  1. We could use some of your expertise on our site which is a student resource base, particularly for Australian students. We have a help forum for students, who often ask questions. We expect many questions soon once most students start using the Classpad.

  2. Sure Sean.. if there's something I can help with I'll post away.. Thanks for the comment!

  3. Thank you very much!

  4. this has helped me so much with my end of unit test, finding it complicated to work out other methods, this was perfect, thank you!

  5. You're welcome.. Maybe it's time to write a few more!

  6. Thank you so much this was actually so helpful!
    I was using Normal PD and was wondering why it wouldn't work :-)

  7. thank you so so much. i'm the only one in my school with this calculator and none of the teachers know how to use it. you just saved me from failing

  8. Awesome, thank you so much. Maths actually makes sense now!!! You are amazing, thankyou so sosoososososo much :)

  9. Hi, I'm just wondering what to do if we just has a upper value, i.e. P(X<1)?

  10. put in -infinity as the lower bound. The symbol is in the soft keyboard


Hi, thanks for leaving a comment.. it's good to hear what people think!