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.
81, 84, 87.
81, 84, 87, 90, 93, 96, 99
The composite numbers are: 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86 ,87, 88
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