The summary statistics for 2 independent datasets from a population are as follows: Sample size | Sample mean Sample standard deviation x data 18 m 5.3 1.0 Sx y data 15 0 4.1 1.5 sy Compute the mean and the variance of the combined dataset 2 . combined mean = Ext zy mt n = mat ny m tn = 18/ 5. 3 ) + 15 ( 4-1 ) = 4.75 ( 3d.p) 18 + 15 combined varience = Sxc 2 ( xx -1 ) + sy2 Ly-1) cty -2 = 12 ( 17 ) + 1.52 ( 14 ) 48-5 = 156 ( 30 p ) 3 /