40.6 is the answer to the problem
Hope it's 30. .....................
(A)
P(<em>X</em> < 61.25) = P((<em>X</em> - 55.4)/4.1 < (61.25 - 55.4)/4.1)
… ≈ P(<em>Z</em> ≤ 0.1427)
… ≈ 0.5567
(B)
P(<em>X</em> > 46.5) = P((<em>X</em> - 55.4)/4.1 > (46.5 - 55.4)/4.1)
… ≈ P(<em>Z</em> > -2.1707)
… ≈ 1 - P(<em>Z</em> ≤ -2.1707)
… ≈ 0.9850
It's a rational number because 25 is perfect square, taking the square root gives the rational integers +5 or -5
3x+2y=5.44
it's a two variable problem which can't be solved algebraically unless you are given the weight of one of the balls.
