43 and 5/6 because 12 and 1/4*2 is 24 and 1/2 then 9 and 2/3*2 is 19 and 1/3 and when you add that you get 43 and 5/6
I believe if that says three minus four times three minus five or three plus negative four times three plus negative five (same thing) then the answers should be positive two (2.)
If you would like to calculate the arithmetic mean, geometric mean, and harmonic mean from the following averages, you can calculate this using the following steps:
averages: 56.4, 59.8, 55.8
the number of values: 3
arithmetic mean:
(56.4 + 59.8 + 55.8) / 3 = 57.33
geometric mean:
(56.4 * 59.8 * 55.8)^(1/3) = 57.31
harmonic mean:
3 / (1/56.4 + 1/59.8 + 1/55.8) = 57.28