The scores of students on a standardized test are normally distributed with a mean of 300 and a standarddeviation of 40.
(a) What proportion of scores lie between 220 and 380 points?
(b) What is the probability that a randomly chosen student scores is below 260?
(c) What percent of scores are above 326.8 points?

Answer: Third Choice. 20

Concept:

Here, we need to know the idea of a slope.

In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line.

Slope = Rise / Run = Δy / Δx = (y₂ - y₁) / (x₂ - x₁)

Solve:

STEP ONE: Select two points on the line that intersects with the grids

A (0, 5)

B (1, 25)

STEP TWO: Apply the formula

Slope = (y₂ - y₁) / (x₂ - x₁)

Slope = (25 - 5) / (1 - 0)

Slope = 20 / 1

Slope = 20

Hope this helps!! :)

Please let me know if you have any questions

Answer:

20

Step-by-step explanation:

We can find the slope of the line by using the slope formula

Slope = (y2 - y1)/(x2-x1)

Where the x and y values are derived from points chosen on the line

The points chosen may vary but I have chosen (1,25) and (2,45)

Now that we have chosen the points let's define our variables ( our variables are x1 x2 y1 and y2 )

x1 is the x value of the first point chosen.The x value of the first point chosen is 1 so x1 = 1

x2 is the x value of the second point chosen. The x value of the second point chosen is 2 so x2 = 2

y1 is the y value of the second point chosen. The y value of the first point chosen is 25 so y1 = 25

y2 is the y value of the second point chosen. The y value of the second point chosen is 45 so y2 = 45

Now to find the slope we simply plug in the values of the variables into the formula

Formula: (y2 - y1)/(x2-x1)

Variables: x1 = 1, x2 = 2, y1 = 25, y2 = 45

Plug in values

(45-25)/(2-1)

Subtract top numbers

(20)/(2-1)

Subtract bottom numbers

20/1

Simplify

The slope is 20

[tex]\\ \sf\longmapsto \frac{x}{6} - \frac{y}{3} = 1 \\ \\ \sf\longmapsto \frac{x - 2y}{6} = 1 \\ \\ \sf\longmapsto x - 2y = 6 \\ \\ \sf\longmapsto x = 6 + 2y[/tex]

Answer:

The maximum value of f(x) occurs at:

[tex]\displaystyle x = \frac{2a}{a+b}[/tex]

And is given by:

[tex]\displaystyle f_{\text{max}}(x) = \left(\frac{2a}{a+b}\right)^a\left(\frac{2b}{a+b}\right)^b[/tex]

Step-by-step explanation:

Answer:

Step-by-step explanation:

We are given the function:

[tex]\displaystyle f(x) = x^a (2-x)^b \text{ where } a, b >0[/tex]

And we want to find the maximum value of f(x) on the interval [0, 2].

First, let's evaluate the endpoints of the interval:

[tex]\displaystyle f(0) = (0)^a(2-(0))^b = 0[/tex]

And:

[tex]\displaystyle f(2) = (2)^a(2-(2))^b = 0[/tex]

Recall that extrema occurs at a function's critical points. The critical points of a function at the points where its derivative is either zero or undefined. Thus, find the derivative of the function:

[tex]\displaystyle f'(x) = \frac{d}{dx} \left[ x^a\left(2-x\right)^b\right][/tex]

By the Product Rule:

[tex]\displaystyle \begin{aligned} f'(x) &= \frac{d}{dx}\left[x^a\right] (2-x)^b + x^a\frac{d}{dx}\left[(2-x)^b\right]\\ \\ &=\left(ax^{a-1}\right)\left(2-x\right)^b + x^a\left(b(2-x)^{b-1}\cdot -1\right) \\ \\ &= x^a\left(2-x\right)^b \left[\frac{a}{x} - \frac{b}{2-x}\right] \end{aligned}[/tex]

Set the derivative equal to zero and solve for x:

[tex]\displaystyle 0= x^a\left(2-x\right)^b \left[\frac{a}{x} - \frac{b}{2-x}\right][/tex]

By the Zero Product Property:

[tex]\displaystyle x^a (2-x)^b = 0\text{ or } \frac{a}{x} - \frac{b}{2-x} = 0[/tex]

The solutions to the first equation are x = 0 and x = 2.

First, for the second equation, note that it is undefined when x = 0 and x = 2.

To solve for x, we can multiply both sides by the denominators.

[tex]\displaystyle\left( \frac{a}{x} - \frac{b}{2-x} \right)\left((x(2-x)\right) = 0(x(2-x))[/tex]

Simplify:

[tex]\displaystyle a(2-x) - b(x) = 0[/tex]

And solve for x:

[tex]\displaystyle \begin{aligned} 2a-ax-bx &= 0 \\ 2a &= ax+bx \\ 2a&= x(a+b) \\ \frac{2a}{a+b} &= x \end{aligned}[/tex]

So, our critical points are:

[tex]\displaystyle x = 0 , 2 , \text{ and } \frac{2a}{a+b}[/tex]

We already know that f(0) = f(2) = 0.

For the third point, we can see that:

[tex]\displaystyle f\left(\frac{2a}{a+b}\right) = \left(\frac{2a}{a+b}\right)^a\left(2- \frac{2a}{a+b}\right)^b[/tex]

This can be simplified to:

[tex]\displaystyle f\left(\frac{2a}{a+b}\right) = \left(\frac{2a}{a+b}\right)^a\left(\frac{2b}{a+b}\right)^b[/tex]

Since a and b > 0, both factors must be positive. Thus, f(2a / (a + b)) > 0. So, this must be the maximum value.

To confirm that this is indeed a maximum, we can select values to test. Let a = 2 and b = 3. Then:

[tex]\displaystyle f'(x) = x^2(2-x)^3\left(\frac{2}{x} - \frac{3}{2-x}\right)[/tex]

The critical point will be at:

[tex]\displaystyle x= \frac{2(2)}{(2)+(3)} = \frac{4}{5}=0.8[/tex]

Testing x = 0.5 and x = 1 yields that:

[tex]\displaystyle f'(0.5) >0\text{ and } f'(1) <0[/tex]

Since the derivative is positive and then negative, we can conclude that the point is indeed a maximum.

Therefore, the maximum value of f(x) occurs at:

[tex]\displaystyle x = \frac{2a}{a+b}[/tex]

And is given by:

[tex]\displaystyle f_{\text{max}}(x) = \left(\frac{2a}{a+b}\right)^a\left(\frac{2b}{a+b}\right)^b[/tex]

Answer:

270.47625

Step-by-step explanation:

249 is the original price

(249/100) · 8.625 = 21.47625 the tax total

249 + 21.47625 = 270.47625

9514 1404 393

Answer:

  9.6 billion

Step-by-step explanation:

The population multiplier is 1+1.1% = 1.011 each year. After 52-19 = 33 years, the multiplier will be 1.011^33 ≈ 1.4348.

When the student is 52, the population of the world will be about ...

  6.7 billion × 1.4348 ≈ 9.6 billion

12/16 = (3x-12)/(2x+8)

16(3x-12)=12(2x+8)

48x-192=24x+96

48x-24x=192+96

24x=288

X=288/24

X=12

3x-12

=(12x3)-12

=36-12

=24

C is the answer

Hope this helps!

Answer:

48

Step-by-step explanation:

2x+8=3x-12(ABCP ~FDQE)

2x-3x= -8-12

-x= -20

x=20

now,

CP=3x-12

3*20-12

48

Answer:

ok um last person was rude but your answer is A

Step-by-step explanation:

Answer:

15/4

Step-by-step explanation:

sin60 =z/15

z=15sin60 =(15√3)/2

cos30 =b/z

b = zcos30 = (15√3)/2 * √3/2 = 45/4

a = 15-b = 15-45/4 = 15/4

The value of a is 15/4

A right triangle is defined as a triangle in which one angle is a right angle or two sides are perpendicular.

According to the given figure,

Here is a right triangle

Let, The hypotenuse = 15

perpendicular = z and base = 15 = a + b

⇒ sin60 = perpendicular/hypotenuse = z/15

⇒ z = 15sin60 = (15√3)/2

⇒ cos30 = base/hypotenuse = b/z

⇒ b = zcos30 = (15√3)/2 * √3/2 = 45/4

⇒ a + b = 15

Substitute the value of b in the above equation,

⇒ a = 15-b = 15-45/4 = 15/4

Hence, the value of a is 15/4.

Learn more about the right triangle here:

brainly.com/question/6322314

#SPJ6

Answer:

Area of rectangle = 2H² - 5H

Step-by-step explanation:

Translating the word problem into an algebraic expression, we have;

Length =2H - 5

To write the algebraic expression to model the area of the rectangle;

Mathematically, the area of a rectangle is given by the formula;

Area of rectangle = L * H

Where;

Substituting the values into the formula, we have;

Area of rectangle = (2H - 5)*H

Area of rectangle = 2H² - 5H

Given the definition above and the fact that top points of the function are at y=9 and the low point are at y=1, the center line must be halfway at y=5.

the amplitude therefore is 4. it's also just half the difference of 1 and 9.

I did this graphically with desmos. Doing it algebraicly would have taken much more time i guess.

Step-by-step explanation:

hope it will help u

hope it will help u please mark me as brillient...

Answer:

939 is the answer

Step-by-step explanation:

plz Mark me as the brainlist

Answer:

This variation is a source of

response error.

Step-by-step explanation:

A response error shows the lack of accuracy in the customer responses to the survey questions.  A response error can be caused by a questionnaire that requires framing improvements, misinterpretation of questions by interviewers or respondents, and errors in respondents' statements.  Some responses are influenced by the answers provided to previous questions, which introduces response bias.

Answer:

There are a few rules that we can use here:

ln(a^x) = x*ln(a)

ln(a) - ln(b) = ln(a/b)

ln(1) = 0

So here we want to expand:

ln(1/49^k)

First we can use the second property to get:

ln(1/49^k) = ln(1) - ln(49^k)

using the third property, we have:

ln(1/49^k) = ln(1) - ln(49^k) = 0 - ln(49^k)

ln(1/49^k) =  - ln(49^k)

Now we can use the first property to get:

ln(1/49^k) =  - k*ln(49)

Now we can use the fact that:

49 = 7*7 = 7^2

then:

- k*ln(49) = -k*ln(7^2) = -2*k*ln(7)

So we have:

ln(1/49^k) = (-2*ln(7))*k

We can expand it anymore because this is a real number  "(-2*ln(7))" times a variable k.

Answer:

Step-by-step explanation:

Answer:

37°

Step-by-step explanation:

that is the procedure above

Answer:

2977.96 =x

Step-by-step explanation:

8 = In(x + 3) ​

Raise each side to the base of e

e^8 = e^ ln(x+3)

e^8 = x+3

Subtract 3 from each side

e^8  -3 = x+3-3

e^8    -3= x

2977.95798 = x

Rounding to the nearest hundredth

2977.96 =x

Answer:

[tex]\displaystyle x = 2977.96[/tex]

General Formulas and Concepts:

Pre-Algebra

Algebra II

Step-by-step explanation:

Step 1: Define

Identify

[tex]\displaystyle 8 = ln(x + 3)[/tex]

Step 2: Solve for x

Answer:

84.7

Step-by-step explanation:

of is another way to say multiply so what your doing is muliplying all the numbers

Answer:

84.7

Step-by-step explanation:

SEE THE IMAGE FOR SOLUTION

HOPE IT HELPS

HAVE A GREAT DAY

Step-by-step explanation:

SO, OT is parallel to the vector a+2b

Answer:

Step-by-step explanation:

TOM / 6.02 years

~~~~~~~~~~~~~~~~~~~~~~

Tom: 2000(1.02)^15 =  $2,691.74  

Jerry: 1800(1.025)^15 =  $2,606.94

TOM has more money after 15 years...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

6000 = 2000(1.02)^t

3=(1.02)^t

ln(3) = t * ln(1.02)

t = ln(3)/ln(1.2)

t = 6.02 years  

Answer:

x=–2

Step-by-step explanation:

x-8=-10

x=-10-8

x=–2

Answer:

-8= -10

, = -10+8

, = -2

Answer:

279+x

Step-by-step explanation:

Emily + Yani + Joyce=3209 stickers

how many stickers does Emily have than Joyce:

(279+2x)-(x)

279+2x-x

=279+x

Answer:

1/5

Step-by-step explanation:

Answer:

95

Step-by-step explanation:

Use the mean formula: mean = sum of elements / number of elements

Plug in the mean and number of elements, then solve for the sum of the numbers:

mean = sum of elements / number of elements

19 = sum of elements / 5

95 = sum of elements

So, the sum of the numbers is 95.

Answer:

Categorical or Continuous.

Step-by-step explanation:

Because the red appears in each colours (continuous)

Answer:

(0.3478, 0.5522)

Step-by-step explanation:

Given:

Total number of red marbles, x = 45

Total number of marbles, n = 100

Phat = x / n = 45 / 100 = 0.45

The confidence interval, C.I is given by :

Phat ± Zcritical * standard error

Phat ± Zcritical * √Phat(1 - Phat) / n

Zcritical at 96% = 2.0537

The standard error = √Phat(1 - Phat) / n

S.E = √(0.45 * 0.55) / 100 = 0.0497493

C.I = 0.45 ± (2.0537 * 0.0497493)

C.I = 0.45 ± 0.10217013741

C. I = (0.3478, 0.5522)

Answer:

Step-by-step explanation:

-Total column

30 students in the class

12 male , so 30-12 = 18 female

-Pencils column

21 students prefer pencils

12 female that prefer pencils , 21-12 = 9 male that prefer pencils

-Total row

21 students prefer pencils

30 students total, 30-21 = 9 students prefer pens

-Pens column

12 students male -9 students male prefer pencil =3  students male prefer pens

18 students female -12 students female prefer pencil =6  students female prefer pens

-to calculate the % always find the equivalent fraction of

30 students/ 100% = number of students you have / ?%

example: for male that prefer pencils we have 30/100 = 9/? so

? = 100*9 /30 =30%

Answer:

The answer is "2"

Step-by-step explanation:

When we check the points where the x is -2

by calculating the "y-value":

It is 2, right?  

it implies that [tex]f(-2)=2[/tex]

that's why the final answer is "2"

Answer:

The length of each side of the city is 250b

Step-by-step explanation:

Given

[tex]a = 20[/tex] --- tree distance from north gate

[tex]b =14[/tex] --- movement from south gate

[tex]c = 1775[/tex] --- movement in west direction from (b)

See attachment for illustration

Required

Find x

To do this, we have:

[tex]\triangle ADE \sim \triangle ACB[/tex] --- similar triangles

So, we have the following equivalent ratios

[tex]AE:DE = AB:CB[/tex]

Where:

[tex]AE = 20\\ DE = x/2 \\ AB = 20 + x + 14 \\ CB = 1775[/tex]

Substitute these in the above equation

[tex]20:x/2 = 20 + x + 14: 1775[/tex]

[tex]20:x/2 = x + 34: 1775[/tex]

Express as fraction

[tex]\frac{20}{x/2} = \frac{x + 34}{1775}[/tex]

[tex]\frac{40}{x} = \frac{x + 34}{1775}[/tex]

Cross multiply

[tex]x *(x + 34) = 1775 * 40[/tex]

Open bracket

[tex]x^2 + 34x = 71000[/tex]

Rewrite as:

[tex]x^2 + 34x - 71000 = 0[/tex]

Expand

[tex]x^2 + 284x -250x - 71000 = 0[/tex]

Factorize

[tex]x(x + 284) -250(x + 284)= 0[/tex]

Factor out x + 284

[tex](x - 250)(x + 284)= 0[/tex]

Split

[tex]x - 250 = 0 \ or\ x + 284= 0[/tex]

Solve for x

[tex]x = 250 \ or\ x =- 284[/tex]

x can't be negative;

So:

[tex]x = 250[/tex]

Step-by-step explanation:

jejejebe. s shs sjs sibskkw

Answer:

y = 2/5x + 1/5

Step-by-step explanation:

y = 2/5x + b

-1 = 2/5(-3) + b

-1 = -6/5 + b

1/5 = b