Answer:
Step-by-step explanation:
[4 2] * -2 5 = [ 4*-2 + 2*7 4*5+2*-1]
7 -1
= [-8+14 20-2]
= [6 18]
Answer:
Mean value is 0 and standard deviation is 1 after all test scores have been standardized by converting them to z-scores using z
Step-by-step explanation:
In a standard normal distribution (also called as <em>Gaussian distribution</em>) all values of the sample can be projected to a normal distribution with mean 0 and standard deviation 1 using their z-scores.
z-score of a value X can be calculated as follows:
z=
where
- 50 is the <em>mean of the test scores</em>
- 6 is the <em>standard deviation of test scores</em>
Basically you're solving for both variables here.
I prefer elimination method so that is what I used.
I started off by multiplying each equation in order to get one of the variables at the same value so it would be possible to cancel it out.
Multiplying the first equation by 3 gave me,
12x + 15y = 69
Then I multiplied the second equation by 4,
-12x + 28y = -56
As you can see, it's not possible to cancel out the x variable.
12x + 15y = 69
+(-12x + 28y = -56)
_____________
13y = 13
Then just solve for y which gives you -1.
After you have one variable solved simply insert it into one of the original equations to find the other variable.
4x + 5(-1) = 23
4x - 5 = 23
4x = 28
x = 7.
And there you have it! Hope this helped!
Answer:
this may be wrond but I think it is -12 m/s
Step-by-step explanation:

Answer: 4π cm or 12.56 cm
Step-by-step explanation: To find the circumference of this circle, start with the formula for the circumference of a circle which is C = 2πr.
Since the radius is 2 centimeters, we can
plug in 2 centimeters for <em>r</em> in the formula.
So we have (2)(π)(2 cm) which is equal to 4π cm.
So the circumference of this circle is 4π cm.
Remember that π is approximately equal to 22/7 or 3.14 so we can estimate the value of the circumference by plugging in 3.14 for π.
So we have (4)(3.14) which is equal to 12.56.
So the circumference of the circle is
approximately equal to 12.56 cm.