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.
Equation of a line that is perpendicular to given line is
.
Equation of a line that is parallel to given line is
.
Solution:
Given line
.
Slope of this line,
= 



Slope of perpendicular line, 
Passes through the point (–7, 5). Here
.
Point-slope formula:



Subtract 7 from both sides, we get

Equation of a line that is perpendicular to given line is
.
To find the parallel line:
Slopes of parallel lines are equal.


Passes through the point (–7, 5). Here
.
Point-slope formula:


Subtract 7 from both sides,

Equation of a line that is parallel to given line is
.
Answer:
-2, -6
Step-by-step explanation:
using cramer rule
5 -3
-2 -1
calculatiing the determinant = (5 x-1) - (-3x-2) = -5 -(6) = -5-6=-11
using cramer rule
to calculate x we change the coefficient of x with the answer (8,10)
8 -3
10 -1
we calculate determinant = (8x-1)-(-3x10) = -8-(-30) = -8+30 =22
to calculate x
22/-11= -2
to calculate y we change the coefficient of y with the answer (8,10)
5 8
-2 10
we calculate determinant = (5x10)-(8x-2) = 50 -(-16) = 50 +16=66
to calculate y
66/-11= -6
Answer:B
Step-by-step explanation: