12.6 × 0.25 = 3.15
i hope this helps
Answer:
see explanation
Step-by-step explanation:
In 13 - 17
Consider the factors of the constant term which sum to give the coefficient of the x- term
13
x² - x - 42 = (x - 7)(x + 6)
15
x² + x - 6 = (x + 3)(x - 2)
17
x² - 27x + 50 = (x - 25)(x - 2)
19
r² - 25 ← is a difference of squares and factors in general as
a² - b² = (a - b)(a + b) , thus
r² - 25
= r² - 5² = (r - 5)(r + 5)
To solve for proportion we make use of the z statistic.
The procedure is to solve for the value of the z score and then locate for the
proportion using the standard distribution tables. The formula for z score is:
z = (X – μ) / σ
where X is the sample value, μ is the mean value and σ is
the standard deviation
when X = 70
z1 = (70 – 100) / 15 = -2
Using the standard distribution tables, proportion is P1
= 0.0228
when X = 130
z2 = (130 – 100) /15 = 2
Using the standard distribution tables, proportion is P2
= 0.9772
Therefore the proportion between X of 70 and 130 is:
P (70<X<130) = P2 – P1
P (70<X<130) = 0.9772 - 0.0228
P (70<X<130) = 0.9544
Therefore 0.9544 or 95.44% of the test takers scored
between 70 and 130.
Answer:
x² - 3x - 10 = (x - 5) (x + 2)
x² - 3x - 18 = (x + 3) (x - 6)
Step-by-step explanation:
<u>x² - 3x - 10</u>
x² + 2x - 5x - 10
x(x + 2) - 5(x + 2)
(x - 5) (x + 2)
<u>x² - 3x - 18</u>
x² - 6x + 3x - 18
x(x - 6) + 3(x - 6)
(x + 3) (x - 6)
<u>-TheUnknown</u><u>S</u><u>cientist</u>
X=7
7x-2=5x+12
+2. +2
7x=5x+14
-5x -5x
2x=14
÷2 ÷2
x=7
