81 84 87
81, 84, 87.
765
87
Assuming that series is 88, 87, 85, 81, 73, 57 the next number is 25. The difference each time is twice the previous difference: 88 → 87 : 88 - 87 = 1 87 → 85 : 87 - 85 = 2 = 1 x 2 85 → 81 : 85 - 81 = 4 = 2 x 2 81 → 73 : 81 - 73 = 8 = 4 x 2 73 → 57 : 73 - 75 = 16 = 8 x 2 → next difference is 16 x 2 = 32 → next number is 57 - 32 = 25
85.
For the set (87 81 75 75 75 70 62 62 62 62 62 56 56): The mean is 68.076923 repeating The median is 62 The mode is 62
81 84 87
79
The median is 87.
The composite numbers are: 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86 ,87, 88
81, 84, 87, 90, 93, 96, 99
81, 84, 87.
62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86, 87, 88.60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86, 87, 88, 90
81, 84, 87
80, 81, 82, 84, 85, 86, 87, 88, 90
80, 81, 82, 84, 85, 86, 87, 88, 90