Statistical Significance between two Means

Question

Over a 7 year period, an event happens 126 times during 154 opportunities for this kind of event to happen. Over the next 8 years, the same event happens 142 times during 169 opportunities for this kind of event to happen.

That's an average of 1.22/opportunity in period 1, and .84/opportunity in period 2.

Is the .38 less occurances statistically significant?

Answer 1

First of all, this question is misstated.

 

126 out of 154 opportunities is 0.82, not 1.22

 

The difference between the 0.82 and 0.84 are not statistically signoficant.