X = (10 x 6) + (20 x 15) + (27 x 19) + (34 x 11) + (41 x 8) + (48 x 6) + (55 x 3) + (62 x 2) / 70
X = 60 + 300 + 513 + 374 + 328 + 288 + 165 + 124 / 70
X = 2072 / 70
X = 29,46
Varians
S2 = (6 – 29.46)2 + (15 – 29.46)2 + … + (2 – 29.46)2
S2 = 5614.40 + 198.36 + 168.76 + 25.92 + 19.36 + 15.36 + 1189.76 + 1679.84 / 69
S2 = 8752.76 / 69
S2 = 126.73
Deviasi standar