Answer
1)median = 57.5
2)mode = 64
3)mean = 55.65
4)trimmed mean = 52.4118
Work Step by Step
Rearrange the data from the smallest to the largest
35, 38, 39, 40, 44, 45, 50, 53, 55, 57, 58, 59, 61, 62, 64, 64, 67, 71, 74, 77
median = (10th + 11th)/2
=(57+58) / 2
=57.5
2) 64 appeared 2 times in the data set so became the mode of the data set
3) n = 20
mean=
(35+38+39+40+44+45+50+53+55+57+58+59+61+62+64+64+67+71+74+77)/20
=55.65
4)% trimmed = 15%
trimmed n = 20 * 0.15 = 3
trimmed data : 35, 38, 39, 40, 44, 45, 50, 53, 55, 57, 58, 59, 61, 62, 64, 64, 67
last 3 number ( 71,74,77) are removed since they have the greatest gap from the previous digit (67 and 71) compared to (35 and 38)
trimmed mean =
=(35+38+39+40+44+45+50+53+55+57+58+59+61+62+64+64+67)/17
=52.4118
