8.
In a class there are 11 boys and 19 girls.
The mean weight of all 30 children is 32.85 kg.
The mean weight of the 11 boys is 31.9 kg.
Work out the mean weight of the 19 girls.

Answers

Answer 1

i think the question is not correct write it again or attach the pic ic

Answer 2

The mean of a data set is the sum of all data elements divided by its count.

The mean weight of the 19 girls is 33.4 kg

Let

[tex]b \to[/tex] boys

[tex]g \to[/tex] girls

[tex]n \to[/tex] the total population

So:

[tex]b = 11[/tex]

[tex]\bar x_b = 31.9[/tex]

[tex]g = 19[/tex]

[tex]n = 30[/tex]

[tex]\bar x = 32.85[/tex]

The mean of all students is calculated as follows:

[tex]\bar x = \frac{\sum x}{n}[/tex]

So, we have:

[tex]\bar x = \frac{\bar x_b \times b + \bar x_g \times g}{n}[/tex]

Substitute known values

[tex]32.85 = \frac{31.9 \times 11 + \bar x_g \times 19}{30}[/tex]

[tex]32.85 = \frac{350.9 + \bar x_g \times 19}{30}[/tex]

Multiply through by 30

[tex]30 \times 32.85 = 350.9 + \bar x_g \times 19[/tex]

[tex]985.5 = 350.9 + \bar x_g \times 19[/tex]

Collect like terms

[tex]985.5 -350.9 = \bar x_g \times 19[/tex]

[tex]634.6 = \bar x_g \times 19[/tex]

Divide through by 19

[tex]33.4 = \bar x_g[/tex]

[tex]\bar x_g = 33.4[/tex]

Hence, the mean weight of the girls is 33.4 kg

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Related Questions

what is the value ofny when -5 y-7/9

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Is there answers to this question?

Which of the following is the slope of a line that passes through the points (-5, 10) and (15, 2)

Answers

Answer:

(4) -2/5

Step-by-step explanation:

Rise/run

In Triangle ABC. AB = 5, BC=8. and AC = 7. Name the largest angle of triangle ABC

Answers

i think its A

Step-by-step explanation:

Translate this sentence into an equation. 99 is the product of Chrissy's age and 9 Use the variable c to represent Chrissy's age.

Answers

Answer:

[tex]9c=99\\[/tex]

Step-by-step explanation:

Product means multipulcation

So it must be 9c = 99

Answer:

99=c×9

Step-by-step explanation:

Chrissy =c

99=c×9

that will be your answer because you have been told to write an equation not to solve.

Evaluate the function w=-5x-1 when x=-3,0, and 8.

Answers

When x = -3;

w = -5(-3) - 1

w = 15 - 1

w = 14

When x = 0;

w = -5(0) - 1

w = 0 - 1

w = -1

When x = 8;

w = -5(8) - 1

w = -40 - 1

w = -41

Best of Luck!

Radius
Diameter: 26 inches
Circunference :
Area:

Answers

Answer:

Radius is 13

Circumference  = 26π

Area is 169π

Step-by-step explanation:

use the radius, circumference, and area formulas.

Radius is 13

Circumference  = 26π

Area is 169π

substitute pi for 3.14, 3, etc if needed

John had 30 sneakers, with 18 of the black. What is the ratio of the sneakers that are not black

Answers

Answer:

18:12

Step-by-step explanation:

30-18=12

18:12

Please help me with the question please ASAP ASAP please please ASAP please please help please please ASAP please please

Answers

Answer:

Ok so since this is a vertical angle you will need to set it in a equation and solve it. Not sure if my answer would be right but let me know. I have attached a picture of me solving it. Hope this helps, thank you !!

What percentage is 18 out of 22

Answers

Answer:

81.8181

Step-by-step explanation:

.......................

81.82% is the percentage of number 18 out of 22.

To find the percentage that 18 represents out of 22, you can use the following formula:

(18 / 22) × 100

Calculating this equation:

(18 / 22) × 100

1800/22

= 81.82

Therefore, 18 is approximately 81.82% of 22.

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ERRE
What is the difference?
4y+6
y-5
2y+ 1
y-5
6y+7
y-5
2y+5
y-5
6y+ 7
-2y-10
2y+5
-2y-10

Answers

y-5

2y+ 1

y-5

6y+7

y-5

2y+5

y-5

6y+ 7

-2y-10

2y+5

-2y-10

Which 2 equations would you use to solve this system?

The difference of two numbers is 4. Their sum is 32. What are the numbers?

• x + y = 4
• x - y = 4
• x + y = 32
• x - y = 32

Answers

Answer:

x-y=4

and

x+y=32 is your equation

difference of two number =x-y is equal to 4

sum of two number=x+y is equal to 32

x-y=4.......(1)

x+y=32.......(2)

adding equation 1 and 2

x-y +x+y=4+32

2x=36

x=36/2=16answer

substituting value of y in equation 1

16-y=4

16-4=y

y=12 answer

please, PLEASE answer this fast! I have 1 hour left before I pass it. Please help :( answer it properly! Thank you in advance.

-This is grade 8 math-


1.What elements belong to Set A and Set B?

2. Is there a repetition of the first elements in the ordered pairs? How about in second elements of the ordered pairs?

3. Does the set of ordered pairs represent a relation?

4. How is a relation represented?

Answers

Answer:

The range is is set of all second pairs (y-coordinates) while the domain is the set of first pairs(x-coordinates)

Step-by-step explanation:

If a person walks 1/2 miles in 3/4 of an hour. What Is the unit rate?

Answers

0.666667 miles per hour i’m pretty sure

Write as a product (5c-3d)^2-9d^2

Answers

Answer:

25c^2-30cd

Step-by-step explanation:

The product of expression is,

⇒ 5c (5c - 6d)

What is an expression?

Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.

Given that;

The expression is,

⇒ (5c - 3d)² - 9d²

Now, We can write the expression in form of product as;

⇒ (5c - 3d)² - 9d²

⇒ (5c - 3d)² - (3d)²

⇒ (5c - 3d - 3d) (5c - 3d + 3d)

⇒ (5c - 6d) (5c)

⇒ 5c (5c - 6d)

Thus, The product of expression is,

⇒ 5c (5c - 6d)

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Lines Line A E and Line G H are parallel in the image below. The image will be used to prove that the sum of the measures of the interior angles of Triangle C G H is 180°.

Lines A E and G H are parallel. Angles F and C are congruent.

Which statement would be included in the proof of why Measure of angle C + measure of angle G + measure of angle H = 180 degrees.?
Angles F and H are congruent.
Angles C and E are congruent.
Angles A and G are congruent.
Angles F and C are congruent.

Answers

Answer:

he corect f and c

Step-by-step explanation:

The answer would be F and C

Explanation: I got it right on the test I took.

Can I get some help with this question

Answers

Question :

If a⁵ = 3⁵, simplify (2a)⁷ ?

3⁷3⁸6⁶6⁷

Answer :

D option 6⁷ is the right answer.

Explanation :

Given :

a⁵ = 3⁵

To Find :

(2a)⁷

Solution :

As, we have a⁵ = 3⁵

We know that if powers are equal then the base are also equal. In a⁵ = 3⁵, powers are equal on both sides so base will also be equal.

∴ a = 3

Now, we have to find (2a)⁷, so by substituting a = 3, we have :

⟹ (2a)⁷ = (2 × 3)⁷

⟹ (2a)⁷ = (6)⁷

⟹ (2a)⁷ = 6⁷

Therefore, correct answer is 6⁷.

Hence, correct option is D.

Find the area of equilateral triangle with side a. Please answer with completely simplified exact values. Answer: A = sq. Units

Answers

Solution :

It is given that the length of a side of a triangle is given by 'a'.

It is an equilateral triangle.

So the three sides will be of equal length and is a, a, a units.

Now the semi perimeter of the equilateral triangle is given by :

[tex]$S=\frac{a+a+a}{2}$[/tex]

  [tex]$=\frac{3}{2}a$[/tex]

Therefore, using the Heron's formula, we can find the area of the equilateral triangle.

Area of the equilateral triangle is given by :

[tex]$A =\sqrt{S(S-a)(S-a)(S-a)}$[/tex]

[tex]$A =\sqrt{\frac{3a}{2}\left(\frac{3a}{2}-a\right)\left(\frac{3a}{2}-a\right)\left(\frac{3a}{2}-a\right)}$[/tex]

[tex]$A=\frac{\sqrt3}{4}a^2$[/tex] square units.

A graduated cylinder that is 24 cm tall can hold 1 L of water.

a. What is the radius of the cylinder? (round to the nearest hundredth)
b. What is the height of the 500 ml mark?
c. The 250 ml mark?

Recall that 1 liter (L) is equal to 1000 milliliters (ml).
Due soon, please I don't understand.

Answers

Answer:

LOL i belive its 200 because i did this exact same thing yesterday for homework and got it right, if its not then i dont know what to say.

Step-by-step explanation:

Raj gave his mother a bouquet of 12 pink and white roses. There were 4 pink roses in the bouquet. Which ratio represents the number of white roses to the total number of roses in the bouquet? One-third One-half Two-thirds Three-fourths

Answers

Two-thirds because if there are 8 white roses and there are 12 total, it would be 8:12, but if you simplify it you get 2:3 as the ratio.

Answer:

The answer would be 2/3 or C

Step-by-step explanation:

I got it

PLEASE HELP THANKS YOU

Answers

u must find the median, the range, and the mode. And that is your answer
Median- 6
Mean- 5.4
Mode- 7

What is the MAD of these numbers 1,1,4,5,5,5,6,7,7,10,10?
Please give an explanation

Answers

Answer:

2.2314

Step-by-step explanation:

To find the mean absolute deviation of the data, start by finding the mean of the data set.

1+1+4+5+5+5+6+7+7+10+10= 61

61÷11= 5.5-2.5= 2.2

Example:

Find the MAD of 2,4,6,8

Step 1 :

Find the mean of the data :

(2+4+6+8) / 4 = 20/4 = 5

Step 2 :

Find the distance between each data and mean.

Distance between 2 and 5 is 3

Distance between 4 and 5 is 1

Distance between 6 and 5 is 1

Distance between 8 and 5 is 3

Step 3 :

Add all the distances :

3+1+1+3 = 8

Step 4 :

Divide it by the number of data :

8 / 4 = 2

In the figure, [tex] \angle[/tex] AOB = [tex] \frac{1}{2} [/tex][tex] \angle[/tex] BOC and [tex] \angle[/tex] BOC = [tex] \frac{2}{3} [/tex][tex] \angle[/tex] COD . Show that [tex] \angle[/tex] COD = [tex] \frac{1}{2} \angle[/tex] AOD mentioning necessary axioms.

~Thanks in advance !

Answers

Answer:

See Below.

Step-by-step explanation:

Statements:                                                        Reasons:

[tex]1)\text{ }\angle AOD=180[/tex]                                                  Straight Angle Theorem

[tex]2)\text{ } \angle AOB+\angle BOC+\angle COD=\angle AOD[/tex]              Angle Addition    

[tex]3)\text{ } \angle AOB+\angle BOC+\angle COD=180[/tex]                   Substitution

[tex]\displaystyle 4)\text{ } \angle AOB=\frac{1}{2}\angle BOC[/tex]                                          Given

[tex]\displaystyle 5)\text{ } \angle BOC=\frac{2}{3}\angle COD[/tex]                                          Given

[tex]\displaystyle 6)\text{ } \frac{1}{2}\angle BOC+\frac{2}{3}\angle COD+\angle COD=180[/tex]              Substitution

[tex]\displaystyle 7)\text{ } \frac{1}{2}\Big(\frac{2}{3}\angle COD\Big)+\frac{2}{3}\angle COD+\angle COD=180[/tex]       Substitution

[tex]\displaystyle 8)\text{ } \frac{1}{3}\angle COD+\frac{2}{3}\angle COD+\angle COD=180[/tex]              Multiplication

[tex]\displaystyle 9)\text{ } 2\angle COD=180[/tex]                                                 Addition

[tex]10)\text{ } \angle COD=90[/tex]                                                   Division Property of Equality

[tex]\displaystyle 11)\text{ } \frac{1}{2}\angle AOD=90[/tex]                                                Division Property of Equality

[tex]\displaystyle 12)\text{ } \angle COD=\frac{1}{2}\angle AOD[/tex]                                        Substitution

Answer:

this is your answer. good luck.

Rita has 10 centimeters of
ribbon. She cuts the
ribbon into 8 equal pieces.
What is the length, in
centimeters, of each
piece of ribbon?

Answers

Answer: 1.25

Step-by-step explanation:

because it is

Find exact value. tan (sin-1 5/8)

Answers

Answer:

The chicken closed the road.

And then he crawled up the spot

and come over the duck

John is planning on building a shelf in the shape of a right triangle. He wants the shelf to be 99 inches at its widest and 4040 inches long. He believes the diagonal will be 41 inches. Is he accurate?

Answers

Given:

Shape of the shelf is a right triangle.

Width of the shelf = 9 inches

Length of the shelf = 40 inches

He believes the diagonal will be 41 inches.

To find:

Whether he is accurate or not.

Solution:

According to the Pythagoras theorem,

[tex]Hypotenuse^2=Perpendicular^2+Base^2[/tex]

Using Pythagoras theorem, find the length of the diagonal.

[tex]Diagonal^2=Width^2+length^2[/tex]

[tex]Diagonal^2=(9)^2+(40)^2[/tex]

[tex]Diagonal^2=81+1600[/tex]

[tex]Diagonal^2=1681[/tex]

Taking square root on both sides.

[tex]Diagonal=\pm \sqrt{1681}[/tex]

But side cannot be negative.

[tex]Diagonal=41[/tex]

Therefore, the length of the diagonal is 41 inches. So, John is accurate.

The graph of a sinusoidal function has a maximum point at (0,5)(0,5)left parenthesis, 0, comma, 5, right parenthesis and then has a minimum point at (2\pi,-5)(2π,−5)left parenthesis, 2, pi, comma, minus, 5, right parenthesis. Write the formula of the function, where xxx is entered in radians.

Answers

The graph and therefore, the sinusoidal function equation is a wave function graph and equation

The formula of the sinusoidal function can be written as follows;

[tex]y = \mathbf{5 \cdot sin\left (\dfrac{1}{2} \cdot \left (x + \dfrac{\pi}{2} \right)\right)}[/tex]

The process of deriving the equation of the sinusoidal function is as follows:

The given parameters of the sinusoidal function are;

The coordinate of the maximum point = (0, 5)

The coordinate of the minimum point = (2·π, -5)

Method:

The general form of the sinusoidal function is y = A·sin(B·(x - h)) + k

From the given coordinates of points on the graph of the sinusoidal wave, the values of A, B, h, and k can be calculated as follows

Solution:

y = A·sin(B·(x - h)) + k

Where;

A = Amplitude = (Maximum y-value - Minimum y-value)/2

∴ A = (5 - (-5))/2 = 5

A = 5

The period, T = 2·π/B = The time to complete a cycle = Time from maximum y-value to another maximum y-value

∴  The period, T  = 2 × (The x-value at maximum y-value - The x-value at minimum y-value)

T = 2 × (0 - 2·π) = -4·π

Given that the period, T represent a scalar quantity, we have T = 4·π

∴ T = 4·π = 2·π/B

B = 2·π/4·π = 1/2

B = 1/2

From the given coordinates, at x = 0, f(x) is maximum, therefore, sin(B·(x - h)) = 1, which gives;

B·(x - h) = π/2

(1/2)·(0 - h) = π/2

h = -π/2

The vertical shift, k =  (Maximum y-value + Minimum y-value)/2

∴ k = (5 + (-5))/2 = 0, there is no vertical shift

Therefore;

The equation of the sinusoidal function is y = 5·sin(1/2·(x - (-π/2)) + 0, from which the equation can be presented as follows;

[tex]y = \mathbf{ 5 \cdot sin\left (\dfrac{1}{2} \cdot \left (x + \dfrac{\pi}{2} \right)\right)}[/tex]

Learn more about sinusoidal functions here

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Answer:

f(x)=5sin((1/2)x + (pi/2))

Step-by-step explanation:

I really need this pls

Answers

Answer:

[tex]\displaystyle m=-1[/tex]

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Algebra I

Reading a Cartesian planeCoordinates (x, y)Slope Formula: [tex]\displaystyle m=\frac{y_2-y_1}{x_2-x_1}[/tex]

Step-by-step explanation:

Step 1: Define

Find points from graph.

Point (2, 0)

Point (0, 2)

Step 2: Find slope m

Simply plug in the 2 coordinates into the slope formula to find slope m

Substitute in points [Slope Formula]:                                                            [tex]\displaystyle m=\frac{2-0}{0-2}[/tex][Fraction] Subtract:                                                                                         [tex]\displaystyle m=\frac{2}{-2}[/tex][Fraction] Divide:                                                                                                [tex]\displaystyle m=-1[/tex]

Calculate the equation of the line through the points (-1, 1), (4.0), and (24,-4).
A y = 5x + 6
B y= 1/5x + 4/5
C y= -5x + 4
D y= -1/5x +4/5

Answers

Good luck to you! Ask if you have any questions.

Answer:

D

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Calculate m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (- 1, 1) and (x₂, y₂ ) = (24, - 4) ← 2 points on the line

m = [tex]\frac{-4-1}{24+1}[/tex] = [tex]\frac{-5}{25}[/tex] = - [tex]\frac{1}{5}[/tex] , then

y = - [tex]\frac{1}{5}[/tex] x + c ← is the partial equation

To find c substitute any of the 3 points into the partial equation

Using (4, 0 ) , then

0 = - [tex]\frac{4}{5}[/tex] + c ⇒ c = 0 + [tex]\frac{4}{5}[/tex] = [tex]\frac{4}{5}[/tex]

y = - [tex]\frac{1}{5}[/tex] x + [tex]\frac{4}{5}[/tex] → D


700, 1200, 1600, 2000, X
If the mean of the five numbers above is 1600, what
is the value of x ?

Answers

Answer:

2500

Step-by-step explanation:

The mean of 700, 1200, 1600, 2000, 2500 is 1600.

Which quadratic equation?

Answers

Answer:

step 1. plug in (-3, 0).

step 2. y = x^2 + x - 6 works and the others dont.

step 3. plug in (-2, -4), (-1, -6), (0, -6), (1, -4), (2, 0)

step 4. All points work in the equation x^2 + x - 6.

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