-20
200
70 + 80 + 70 + 30+ 80 + 80+ 80 = 490
30+70 = 100
The mean value of 100, 70, 70, and 20 is 65
30 + 50 + 70 = 150
the sum of 70 + 30 = 100
20 + 50 = 70.
the sum for 20 + 40 + 70 + 80 = 210
The sum of 70 + 30 + 1250 + 50 + 100 = 1500
205
30
20 + 12 + 32 + 20 + 30 + 72 = 186