Here is dependence between scores and x-values:
where 
is the mean, 
is standard deviation and i changes from 1 to 2.
1. When i=1, 
then
2. When i=2, 
then
Now solve the system of equations:
Subtract first equation from the second:
Then
Answer: the mean is 62, the standard deviation is 20.
Answer:
108 degrees
Step-by-step explanation:
3x+x+6x=10x, 180/10=18 and 18x6 is 108
Answer:
A) Length = 110.4 mm and width = 62.1 mm
B) A = 6855.84 mm²
C) length = 114.7 mm
width = 55.8 mm
Area = 6400.26 mm²
D) Screen with aspect ratio of 16:9 is bigger
Step-by-step explanation:
A) We are told that the aspect ratio of the phone screen = 16:9. This means that the ratio of the length to the width of the screen is 16:9.
To find the side length, we will say that;
length = 16x
width = 9x
Thus, since the edges are perpendicular, then we can use pythagoras theorem since we know that the diagonal is 127 mm
Thus;
(16x)² + (9x²)] = 127²
256x² + 81x² = 16129
337x² = 16129
x² = 16129/337
x = √(16129/337)
x = 6.9
Thus;
length = 16x = 16 × 6.9 = 110.4 mm
width = 9x = 9 × 6.9 = 62.1 mm
Length = 110.4 mm and width = 62.1 mm
B) area of screen is;
A = length × width
A = 110.4 × 62.1
A = 6855.84 mm²
C) We are told that the aspect ratio is now 18.5:9.
Thus;
length = 18.5x
width = 9x
Thus;
(18.5x)² + (9x²)] = 127²
342.25x² + 81x² = 16129
423.25x² = 16129
x² = 16129/423.25
x = √(16129/423.25)
x = 6.2
length = 18.5x = 18.5 × 6.2 = 114.7 mm
width = 9x = 9 × 6.2 = 55.8 mm
Area = 114.7 × 55.8 = 6400.26 mm²
D) Screen with aspect ratio of 16:9 is bigger
Answer:
x = -4
Step-by-step explanation:
You kind of didn't capture the directions in your image, but it looks like maybe they want you to write the equation of the line.
So this is what you need to know: the equation of a vertical (up and down) line is
x = anumber
For future reference on the next question, the equation of a horizontal (flat, left and right) line is
y = anumber
For this question, though, it's vertical.
so x = -4
You can check by picking as many points as you like and find that they ALL have -4 as the x value. Also, you will find the slope formula gives you an answer that is undefined. That's why you can't write an equation using y=mx+b. Hope this helps! I can edit if the question is something wildly different for real.
