When the outliers are removed, how does the mean change? dot plot with 1 on 50, 1 on 76, 1 on 78, 2 on 79, 1 on 80, 1 on 81, 2 on 82, 1 on 83 the mean decreases by 3. the mean increases by 2. the mean increases by 3. there are no outliers.

The mean increases by 3




The original data set is 
{50, 76, 78, 79, 79, 80, 81, 82, 82, 83}

The outlier is 50 because it is not near the group of values from 76 to 83 which is where the main cluster is.

The original mean is M = (50+76+78+79+79+80+81+82+82+83)/10 = 77

If we take out the outlier 50, the new mean is N = (76+78+79+79+80+81+82+82+83)/9 = 80

So in summary so far
old mean = M = 77
new mean = N = 80

The difference in values is N-M = 80-77 = 3

So that's why the mean increases by 3