Please help I will give me with the answer

he test scores on the Chapter 10 mathematics test have a mean of 52 and a standard deviation of 10. Andrea scored 76 on the test

tekilochka [14]

Answer:

Step-by-step explanation:

Hello!

The mean is a measurement of central tendency that shows what is the most expected value of the variable. The standard deviation is a measurement of variability, it shows you how distant or dispersed are the values of a certain population or sample in regards to the value of the mean.

In this example the variable is X: score obtained on a math test.

It's mean is μ= 52 and its standard deviation is σ= 10

To know how many standard deviations away is a value of X concerning the mean you have to first subtract the mean to the value of X, X - μ, and then you have to divide it by σ:

(X - μ)/ σ

If X=76

(76 - 52)/ 10= 2.4

The score obtained by Andrea is 2.4σ away from the mean.

I hope it helps!

3 0

3 years ago

Need help with translation

sergij07 [2.7K]

Answer:

The translation rule will be: (x, y) → (x+3, y+9)

Step-by-step explanation:

As X'Y' is a translation of XY.

As the location of the vertix X is (-4, -9) and the coordinates of vertex Y is (-5, -5).

As X'Y' be the vertices of the translated figure.

So, if we translate the segment XY +3 units in the x-direction and +9 units in the y-direction, i.e.

(x, y) → (x+3, y+9) = (-4+3, -9+9) = (-1, 0) = X'

and

(x, y) → (x+3, y+9) = (-5+3, -5+9) = (-2, 4) = Y'

so, the image X'Y' will have the X' vertice at the location (-1, 0) and Y' vertice at the location (-2, 4).

Therefore, the translation rule will be: (x, y) → (x+3, y+9)

6 0

3 years ago

Write an expression to represent 1 less than the quotient of four and a number X

Daniel [21]

Answer:

x/4-1

Step-by-step explanation:

5 0

3 years ago

Cos^2 x+4sin^2 x/2=1

lana [24]

$Let\ \dfrac{x}{2}=a,\ therefore\ x=2a.\\\\\cos^2x+4\sin^2\dfrac{x}{2}=\cos^22a+4\sin^2a\\\\\text{use}\ \cos2x=\sin^2x-\cos^2x\\\\=(\sin^2a-\cos^2a)^2+4\sin^2a\\\\\text{use}\ (a-b)^2=a^2-2ab+b^2\\\\=(\sin^2a)^2-2(\sin^2a)(\cos^2a)+(\cos^2a)^2+4\sin^2a\\\\=\sin^4a-2\sin^2a\cos^2a+\cos^4a+4\sin^2a\\\\=\underbrace{\sin^4a+2\sin^2a\cos^2a+\cos^4a}_{(*)}-4\sin^2a\cos^2a+4\sin^2a\\\\\text{use}\ (*)\qquad(a+b)^2=a^2+2ab+b^2$

$=\underbrace{(\sin^2a)^2+2\sin^2a\cos^2a+(\cos^2a)^2}_{(*)}-4\sin^2a(\cos^2a-1)\\\\=(\sin^2a+\cos^2a)^2-4\sin^2a(\cos^2a-1)\\\\\text{use}\ \sin^2a+\cos^2a=1\to\sin^2a=\cos^2a-1\\\\=1^2-4\sin^2a(\sin^2a)=1-4\sin^4a=1-(2\sin^2a)^2$

$\cos^22a+4\sin^2a=1\\\\1-(2\sin^2a)^2=1\qquad\text{subtract 1 from both sides}\\\\-(2\sin^2a)^2=0\to2\sin^2a=0\qquad\text{divide both sides by 2}\\\\\sin^2a=0\to\sin a=0\\\\a=k\pi\ for\ k\in\mathbb{Z}\\\\\dfrac{x}{2}=k\pi\qquad\text{multiply both sides by 2}\\\\\boxed{x=2k\pi\ for\ k\in\mathbb{Z}}$

6 0

3 years ago

What is the equation of the line ,in slope intercept form , that passes through (3,-1) and (-1,5)?

Andre45 [30]

Answer:

First lets find the slope through the points (3,-1) and (-1,5)

m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula (note: (x%5B1%5D,y%5B1%5D) is the first point (3,-1) and (x%5B2%5D,y%5B2%5D) is the second point (-1,5))

m=%285--1%29%2F%28-1-3%29 Plug in y%5B2%5D=5,y%5B1%5D=-1,x%5B2%5D=-1,x%5B1%5D=3 (these are the coordinates of given points)

m=+6%2F-4 Subtract the terms in the numerator 5--1 to get 6. Subtract the terms in the denominator -1-3 to get -4

m=-3%2F2 Reduce

So the slope is

m=-3%2F2

Step-by-step explanation:

3 0

3 years ago