Proof by contradiction is a form of proof that establishes the truth or the validity of a proposition, by showing that assuming the proposition to be false leads to a contradiction. I googled this so it may not be correct
3x -x + 8 + 5x - 2 = 10
3x - x + 5x = 10 -8 +2
7x = 4
x = 7/4
P(X<=x) = 1 + 5.486 = 6.486
The z-score of the information given is,
z = (x - µ )/ σ
Where,
µ = mean
σ = standard deviation
From the information given,
x = 3.71
µ = 86
σ = √225 = 15
hence,
z = (3.71 - 86)/15 = -5.486
thus,
P(X<=x) = 1 + 5.486 = 6.486
hence , P(X<=x) = 1 + 5.486 = 6.486
Learn more about variance here brainly.com/question/9304306
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kyle regalara 16 figuras y le quedara 3/4 de ellas