Answer:
7431, 7763, 7604
Step-by-step explanation:
Number of standardized size Z
The observation 7500
Mean U
Standard deviation S
Group 1
7431 7763 7604
U = (7431 + 7763 + 7604)/4
U = -0.736
Z = (X - U)/S
Z = (7500 - 7599.3)/135 = -99.33/135
Z = - 0.736
For first group
Group 2
7514 7798 7831 7708
U = (7514+ 7798+ 7831 +7708 )/4
U = 7712.75
S = 123.27
Z = (X - U)/S
Z = (7500- 7712.75)/123.27 = -212.15/123.27
Z = - 1.721
For second group
Group 3
7691 7512 7756
U = (7691 + 7512 +7756)/3
U = 7652.7
S = 102.84
Z = (X - U)/S
Z = (7500- 7652.7)/102.84 = -152.7/102.84
Z = - 1.4848
For third group
Z1>Z3>Z2
The first group is the answer