# Hypothesis test

1. Dec 12, 2010

### TomJerry

Question : A computer system has 6 I/O channels and the system personnel are reasonably certain that the load on channels is balanced. If X is random variable denoting the index of the channel to which a given I/O operations is directed , that its pmf is assumed to be uniformly distributed. Out of N=150 I/O operation onserved, the number of operations directed to various channels were:
n0 = 22 ; n1 = 23 ; n2 = 29 ; n3 = 31 ; n4 = 26 ; n5 = 19

Test the hypothesis that the load on channels is balanced at 5 percent level of significance.

Solution
I have used the $$\chi$$2 = (O-E)2 / E

where O - obsevred and E is expected

Is this correct or should i be using some other method

2. Dec 13, 2010

### SW VandeCarr

You can use the chi square test $$\chi^2=\sum (O-E)^2/E$$ Do you know how to get E?

Last edited: Dec 13, 2010
3. Dec 13, 2010

### TomJerry

I have taken all the E = $$\Sigma$$xi/6

Is that correct?

4. Dec 14, 2010

### SW VandeCarr

Yes. If each I/O is taken as equally probable, 150/6=25=E.

5. Dec 14, 2010

### TomJerry

Thanks:surprised

6. Dec 14, 2010

### SW VandeCarr

If you're being sarcastic, why did you ask for confirmation in the first place?

Last edited: Dec 14, 2010