# Thread: Goodness of fit test

1. ## Goodness of fit test

lower lim upper lim sample frequency
-3 -2 11
-2 -1 22
-1 0 19
0 1 14
1 2 21
2 3 13

Perform the goodness of fit test at the 10% significance level. Are the residuals normally distributed?
I have the formula as the sum of (((a-e)^2)/e)))
a=sample frequency
e=total number of residuals*area under pdf for that class

but how do I find area under probability distribution function for class width? Pleeeeeasee help

2. Originally Posted by samdmansam
lower lim upper lim sample frequency
-3 -2 11
-2 -1 22
-1 0 19
0 1 14
1 2 21
2 3 13

Perform the goodness of fit test at the 10% significance level. Are the residuals normally distributed?
I have the formula as the sum of (((a-e)^2)/e)))
a=sample frequency
e=total number of residuals*area under pdf for that class

but how do I find area under probability distribution function for class width? Pleeeeeasee help
That depends on the distribution you are testing this data against.

By the look of it you want the uniform distribution on [-3,3], then as each of your intervals is of width 1, the expected frequency for each is (1/6)*totalnumber of observations=100/6~=16.66

RonL