In the early 2000s, ABC Mining Company implemented new safety guidelines. Prior to these new guidelines, management expected there to be no accidents in 45% of the months, one accident in 35% of the months, two accidents in 15% of the months and three or more accidents in 5% of the moths.

Over the last 10 years (120 months), there have been 46 months in which there were no accidents, 40 moths in which there was one accident, 22 months in which there were two accidents , and 12 months in which there were three or more accidents.

Calculate the test statistic.