Update Weighted_Mean.java

Update Standard_Deviation.java

Update Spearmans_Rank_Correlation_Coefficient.java

Update Quartiles.java

Update Poisson_Distribution_2.java

Update Poisson_Distribution_1.java

Update Pearson_Correlation_Coefficient.java

Update Mean_Median_Mode.java

Update Interquartile_Range.java

Update Geometric_Distribution_2.java

Update Geometric_Distribution_1.java

Update Binomial_Distribution_2.java

Update Binomial_Distribution_1.java

Update README.md

Rename Weighted Mean in Java to Weighted_Mean.java