There is no single middle number. 8 and 15 are the two numbers in the middle.
There are 5 numbers in the ordered list: 5 6 8 25 31 So the middle position is [(1+5)/2] = 3 and the middle number is 8. 27 is greater than 8 so continue with the second half of the list. There are 2 number in the reduced ordered list: 25 31 So the middle position is number is [(1+2)/2] = [1.5] = 2 and the middle number is 31. 27 is smaller than 31 so continue with the first half of the reduced list. There is only 1 number left in the reduced ordered list: 25. Since it is not 27, the number being sought is not in the list.
7
It is 31 because it has only two factors which are itself and one
One possibility would be 27. I see here on the odd locations a growing series, adding 8 each time: 15 +8 = 23; 23 +8 = 31; 31 + 8 = 39 For the even locations, you could take a diminishing series, subtracting 4 each time: 35 - 4 = 31; 31 - 4 = 27.
4
31, since it is prime (the rest are composite).
There are 5 numbers in the ordered list: 5 6 8 25 31 So the middle position is [(1+5)/2] = 3 and the middle number is 8. 27 is greater than 8 so continue with the second half of the list. There are 2 number in the reduced ordered list: 25 31 So the middle position is number is [(1+2)/2] = [1.5] = 2 and the middle number is 31. 27 is smaller than 31 so continue with the first half of the reduced list. There is only 1 number left in the reduced ordered list: 25. Since it is not 27, the number being sought is not in the list.
7
27 and 31 are prime.
It is 31 because it has only two factors which are itself and one
35- 4= 31-4= 27-4= 23-4= 19-4= 15-4= 11-4= 7,3,-1....
27
The element with an atomic number between 27 and 31 is cobalt, with atomic number 27.
39
27
One possibility would be 27. I see here on the odd locations a growing series, adding 8 each time: 15 +8 = 23; 23 +8 = 31; 31 + 8 = 39 For the even locations, you could take a diminishing series, subtracting 4 each time: 35 - 4 = 31; 31 - 4 = 27.
an isotope of phosophorus(atomic number 15), with an extra neutron(creating a mass of 15+16+31