Subst for f and t in...
9t+3ft+12 = 9×21 + 3×3×21 + 12 = 390
0.666667 as a fraction is 2/3
For a standard normally distributed random variable <em>Z</em> (with mean 0 and standard deviation 1), we get a probability of 0.0625 for a <em>z</em>-score of <em>Z</em> ≈ 1.53, since
P(<em>Z</em> ≥ 1.53) ≈ 0.9375
You can transform any normally distributed variable <em>Y</em> to <em>Z</em> using the relation
<em>Z</em> = (<em>Y</em> - <em>µ</em>) / <em>σ</em>
where <em>µ</em> and <em>σ</em> are the mean and standard deviation of <em>Y</em>, respectively.
So if <em>s</em> is the standard deviation of <em>X</em>, then
(250 - 234) / <em>s</em> ≈ 1.53
Solve for <em>s</em> :
16/<em>s</em> ≈ 1.53
<em>s</em> ≈ 10.43
Answer:
30x-18
Step-by-step explanation:
(6)(5x+−3)
=(6)(5x)+(6)(−3)
=30x-18
Answer:

Step-by-step explanation:

