probabilities

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sarkal95
Posts: 1
Joined: Fri Oct 24, 2014 2:35 am

probabilities

Postby sarkal95 » Fri Oct 24, 2014 2:47 am

I'm a total rookie at spss. We learnt in class how to calculate probabilities on the software and I thought I calculated it properly but apparently not. The question they're asking is what is the probability of having a bag with 9 (or less) green M&M’s or 6 (or less) blue M&M's

What I did is I calculated the Z for blue M&Ms as well as the mean and SD, and I did the same for the blue.

then I clicked on CDF normal and plugged in the values where they belong.
It looked something like this

CDF(9, mean of green m&ms, SD of green m&m's) + CDF (6, mean of blue m&m's, SD blue m&ms) and it gave me a number ABOVE 1. which is impossible for probabilities. the max is 1. so i'm wondering where I went wrong?

__________

** EXTRA INFO**

my data view looked something like this:

it had columns with the color of each m&ms (red, blue, green, orange, etc). The rows were labeled as the number of the bag (so bag 1, bag 2, bag 3).

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