Topic summary
Bimodal distribution
Extracted from the Wikipedia article Multimodal distribution.
Unimodal vs. bimodal distribution
Pearson in 1894 was the first to devise a procedure to test whether a distribution could be resolved into two normal distributions. This method required the solution of a ninth order polynomial. In a subsequent paper Pearson reported that for any distribution skewness + 1 < kurtosis. Later Pearson showed that