Good day, I do not understand how the values in the second last and the last column is calculated. Could you please assist me? Because for example in the first row: xi - arithmetic mean (45 - 66.3333) does not equal 21.33333. How are the values in those 2 columns calculated? I look forward to your reply.

Solution: x = 66.3333 Class Xi x ; - 5 fix; -x [40;50) 45 21.3333 85.3332 [50;60) 55 11.3333 67.9998 [60;70) 65 1 1.3333 13.3333 [70;80) 75 8.6667 34.6668 [80;90) 85 18.6667 74.6668 [90;100) 95 28.6667 57.3334 Total 30 333.3333 The mean deviation is: MD = - (333.3333) =11.1111 . 30