It is 23 because 17+19+21+23 = 80
19.
the answer is 20-19=1
100. The first nine prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, and 23.
19+36-47=8
The sum of 712 plus 518 is 1230
672.72 repeating
23 and 19
441
3 + 23 7 + 19 13 + 13
The sum is: 11+13+17+19+23 = 83
23 = 8, 33 = 27. Sum 35, difference 19...
17 + 19 + 23 = 59
19 and 23
19 + 21 + 23 = 63
19 + 21 + 23 + 37 = 100 There are 4 numbers so mean = sum/number = 100/4 = 25
that's kinda general. it could be 518 and 1. are you sure its sum? or is it product?