Area under ALL probability distribution curves is 1.0, because all possible outcomes are taken into account.
4.72n - 0.1 = 8 + 0.67n
4.72n - 0.67n = 8 + 0.1
4.05n = 8.1
4.05n/4.05 = 8.1/4.05
n = 2
Justify means plug answer in and verify
so distribute 8(3-7x)=24-56x
143=7+24-56x
143=31-56x
minus 31 both sides
112=-56x
divide both sides by -56
-2=x
justify
plug it back
143=7+8(3-7x)
143=7+8(3-7(-2))
143=7+8(3-(-14))
143=7+8(3+14)
143=7+8(17)
143=7+136
143=143
true
x=-2
10 - nw is less than or equal to 8
n = number