There is a total of 45 boys and girls in a choir.
The mean age of the 18 boys is 16.2 years.
The mean age of the 27 girls is 16.7 years.

Calculate the mean age of all 45 boys and girls.

Answers

Answer 1

Answer:

16.5 year

Step-by-step explanation:

Using, mean = sum/no. *of observations

Here,

=> 16.2 = (sum of ages of boys)/18

=> 16.2 x 18 = sum of ages of boys

=> 291.6 = sum of ages of boys

Similarly, sum of ages of girls = 27 x 16.7 = 450.9

Mean(total) = (sumof agesof boys + girls)/45

Mean = (291.6 + 450.9)/45 = 16.5

Answer 2

Answer:

The mean age of all 45 boys and girls is 16.5years

Step-by-step explanation:

Since the mean age of the 18 boys is 16.2years,

∴ Sum of their ages = 18 × 16.2

                                 = 291.6years

The mean age of the 27 girls is 16.7years

∴ Sum of their ages = 27 × 16.7

                                 = 450.9years

∴ Mean age of all 45 boys and girls = [tex]\frac{291.6 + 450.9}{45}[/tex] years

                                                           = [tex]\frac{742.5}{45}[/tex] years

                                                           = 16.5 years

∴ The mean age of all 45 boys and girls is 16.5 years.


Related Questions

Solve for n.
7n - 4 = 317
n =

Answers

Step-by-step explanation:

[tex]7n - 4 = 317 \\ 7n = 317 + 4 \\ 7n = 321 \\ n = \frac{321}{7} \\ n = 45 \frac{6}{7} [/tex]

Answer:

[tex]n = \frac{321}{7} [/tex]

Step-by-step explanation:

1) Add 4 to both sides.

[tex]7n = 317 + 4[/tex]

2) Simplify 317 + 4 to 321.

[tex]7n = 321[/tex]

3) Divide both sides by 7.

[tex]n = \frac{321}{7} [/tex]

Therefor, the answer is n = 321/7 and in decimal form it would be, 45.857143.

1. Find the surface area of the rectangular prism below.

7 in. 12 in

A. 1620 in2
B. 882 in2
C. 300 in2
D. 810 in2​

Answers

Answer:

I think its c!!!!!!!!!!!!!!!!!

2+2
1+1
5+10
q+3=21 What is q

Answers

Answer:

18

Step-by-step explanation:

21 - 3= 18

/:

Answer:

Step-by-step explanation:

2+2 = 4

1+1 = 2

5+10 = 15

q+3 = 21, q = 21-3 = 18

Or if you meant all of them added together is 21, 2+2+1+1+5+10+q+3=21

q = -3

Which of ratio is equivalent to 3:4 ?
12:9
9: 20
9:12
803 : 804

Answers

Answer:

C

Step-by-step explanation:

3/4 = 9/12

This is because

3 x 3 = 9

4 x 3 = 12

3/4 = 9/12

Hope that helps!

write an equation for the table below representing the relationship between the number of games and the total cost

Answers

Answer:

Answer is the Equation is 2x+2

Answer:

2x+2

Step-by-step explanation:

hope it helpssssss

Please help me 20 points

Find m∠A and m∠B =

Answers

Answer:

96 for b 90 for a

Step-by-step explanation:

Which set of integers is ordered from least to greatest -13 , 4, 0, -8 -5 , -2, 3, 1 -12 , -18 , -4 , 7 -15, 6 , -9 , -21

Answers

Given:

The set of integers in the options.

-13 , 4, 0, -8

-5 , -2, 3, 1

-12 -18 , -4 , 7

-15, 6 , -9 , -21

To find:

The set of integers that is ordered from least to greatest.

Solution:

We know that the larger negative value is the smaller value and the larger positive value is the greater value.

Ordered from least to greatest means first we need to write the smallest value, write the value larger than and the greatest value occurs at the end.

In option A, we have -13 , 4, 0, -8. Here, 4>0. So, the option A is incorrect.

In option B, we have -5 , -2, 3, 1. Here, 3>1. So, the option B is incorrect.

In option C, we have -12 -18 , -4 , 7 Here, -12>-18. So, the option C is incorrect.

In option D, we have -15, 6 , -9 , -21. Here, 6>-9. So, the option D is incorrect.

Therefore, all the options are incorrect.

4x + 3 = x + 2(x + 7)
step by step

Answers

Answer:

x=11

Step-by-step explanation:

4x + 3 = x+ 2x + 14

4x + 3 = 3 x + 14

4x - 3x = 14 -3

x= 14 - 3

x= 11

Answer:

x=11

Step-by-step explanation:

Distribute :

4x + 3 = x + 2( x+ 7)

4x + 3 = x + 2x + 14

Combine like terms :

4x + 3 = x + 2x + 14

4x + 3 = 3 x+ 14

Subtract 3 from both sides of the equation :

4x + 3 = 3x + 14

4x + 3-3 = 3x + 14 -3

Simplify :

what ever way you know how to subtract the numbers you should get this answer :

4x = 3x + 11

Subtract 3 from both sides of the equation :

4x = 3x + 11

4x - 3x = 3x + 11 - 3x

Simplify :

combine like terms

multiply by 1

combine like terms

x= 11

4 A triangle with a height of 3 cm and a base
of x cm is the result of reducing each
dimension by a scale factor of one-third.
The area of the original triangle is
162 cm². What was the original length of
the base?

Answers

Answer:

L = 36

Step-by-step explanation:

"A triangle with a height of 3 cm and a base  of x cm is the result of reducing each  dimension by a scale factor of one-third"

We are looking for the original. This triangle was reduced by 1/3, so we would have to mulitply by 3 to get the original triangle measurements.

height = 3 x 3 = 9

length = x * 3

"The area of the original triangle is  162 cm²."

Area = Base x Height/2

162 = (x*3) * 9/2

324 = (x*3)*9

36 = x*3

x = 12

What was the original length of  the base?"

Length = x * 3

            = 12 * 3

Length = 36

I hope this helped!

In circle M below, m

Answers

Answer:

we have:

AMC = 2ABC

=> 10x - 12 = 2(4x + 6)

<=> 10x - 12 = 8x + 12

<=> 2x = 24

<=> x = 12

with x = 12 => ABC = 4.12 + 6 = 48 + 6 = 54⁰

Answer:54

Step-by-step explanation:

ill mark brainliswt plss help

Answers

Answer:

z = 24

Step-by-step explanation:

35/30 = 7/6

28/7 = 4

6 x 4 = 24

28/24 = 7/6

Answer:

x = 24

Step-by-step explanation:

All you have to do is cross multiply like this..

30 x 28 = 35 x X

=

x = 30 x 28/35

30 x 28 = 840 / 35 =

24

So x is equal to 24

Hope this helps :)

Amelia invests money in an account paying simple interest. She invests $180
and no money is added or removed from the investment. After one year, she
has $187.20. What is the simple percent interest per year?

Answers

Answer:

4%

Step-by-step explanation:

100% represents the starting balance: $180.

Method 1

Express the ending balance as a percentage of the starting balance:

$180

1.04

1.04 times 100=

1.04×100=

104%

Subtract the starting 100% to get the percent interest:

4%

Method 2

$187.20−$180=

$7.20

$180

$7.20

0.04

0.04 times 100=

0.04×100=

4%

if an is defined as a geometric sequence, is the sequence 1/an also a geometric sequence? explain your reasoning.​

Answers

Answer:

Since An/An-1 = r

(1/An)/(1/An-1) = An-1/An = 1/r

so, the ratio between terms is still constant.

Step-by-step explanation:

If an is defined as a geometric sequence, is the sequence 1/an also a

geometric sequence because the ratio between terms remain constant.

What is a geometric sequence and how to find its nth terms?

Suppose the initial term of a geometric sequence is a and the term by which we multiply the previous term to get the next term is r

Then the sequence would look like

[tex]a, ar, ar^2, ar^3, \cdots[/tex]

 (till the terms to which it is defined)

Thus, the nth term of such sequence would be[tex]T_n = ar^{n-1}[/tex]

Since An/An-1 = r

(1/An)/(1/An-1) = An-1/An = 1/r

Therefore, the ratio between terms is still constant.

Learn more about geometric sequence here:

https://brainly.com/question/2735005

#SPJ2

Which expression is equal to x^2- y^5?

Answers

(x2+y5)=(x2-y5),

x^2-y^5 would equal 0

guess who's going to fail ;)



(pls answer)

Answers

Me ;) this sucks im doing a big test school is so stressful
Your answer is c hope it helped ;)

Write an equation of the line that passes through the points (−3,−4) and (0,2).
y=23x−2
y−3=23(x−0)
y−0=23(x−3)
y+0=23(x+3)
which one of them are it

Answers

It should be y=2x+2 it has to be in slope form: y=mx+b
Y+0=23(x+3) is the answer to that question

Please help!!!
Factor the following
[tex]3x^3-x^2y+6x^2y-2xy^2+3xy^2-y^3[/tex]
Show work to receive full credit

Answers

Answer:

(3x - y)(x + y)²

Step-by-step explanation:

3x³ - x²y + 6x²y - 2xy² + 3xy² - y³ =x²(3x - y) + 2xy(3x - y) + y²(3x - y) =(3x - y)(x² + 2xy + y²) = (3x - y)(x + y)²

Answer:

[tex](3x-y)(x+y)^2[/tex]

Step-by-step explanation:

[tex]3x^3-x^2y+6x^2y-2xy^2+3xy^2-y^3[/tex]

Multiply and combine like terms.

[tex]3x^3+xy^2-y^3+5xy^3[/tex]

Consider [tex]3x^3+xy^2-y^3+5xy^3[/tex] as a polynomial over variable x.

[tex]3x^3+5xy^2+y^2x-y^3[/tex]

Find one factor of the form kx^m +n, where kx^m  divides the monomial with the highest power 3x^3  and n divides the constant factor −y^3 . One such factor is 3x−y. Factor the polynomial by dividing it by this factor.

[tex](3x-y)(x^2+2xy+y^2)[/tex]

Consider [tex]x^2+2xy+y^2[/tex]. Use the perfect square formula, [tex]a^2+2ab+b^2[/tex] = [tex](a+b)^2[/tex], where a=x and b=y.

[tex](x+y)^2[/tex]

Rewrite the complete factored expression.

[tex](3x-y)(x+y)^2[/tex]

6 of 7
£25 = 700 rubles, how many £ are in 1,260 rubles?
£

Answers

Answer:

45

Step-by-step explanation:

25 = 700

Y = 1260

Now you need to do cross multiplication .

25 X 1260=700Y

Since it's in a multiplying form you can simplify by dividing 700 by 25

1260=700Y/25

1260=28Y

Y=45

which expression fits this description
.the expression is the quotient of two quantities
. the numerator of the expression is the product of 5 and sum of x and y
. the denominator is the product of negative 8 and x​

Answers

Answer:

Step-by-step explanation:

Match each LCD with the correct pair of rational expressions. LCD = 2(3)(5)(7)(x)(x)

Answers

Answer:

LCD = 2(3)(5)(7)(x)(x) is A

LCD = (x - 3)(x + 1) is D

LCD = (x + 2)(x - 3) is C

LCD = 2(3)(5)(7)(x) is B

GUYSSSSSS!!!SOLVE IT WITH EXPLAIANTION​

Answers

Answer:

Marie Skłodowska Curie (born Maria Salomea Skłodowska (Polish: [ 7 November 1867 – 4 July 1934), was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity. As the first of the Curie family legacy of five Nobel Prizes, she was the first woman to win a Nobel Prize, the first and the only woman to win the Nobel Prize twice, and the only person to win the Nobel Prize in two scientific fields. She was the first woman to become a professor at the University of Paris in 1906.[4]

Step-by-step explanation:

The vertices of GHJ are shown below. If this triangle is translated 2 units right and 1 unit down, what is the coordinate for vertex G'?



G (10, 10)

H (12, 12)

I (14, 14)

A
(12, 10)

B
(10, 9)

C
(12, 9)

D
(12, 14)

Answers

The formula for this translation would be (x,y) to (x+2, y-1), so the coordinate for G’ would be (12, 9)

Please help me with this!!!

Answers

Answer:

True

they intersect at only one point

hope it will help you

your day will full of happiness

Answer:

i think true

Step-by-step explanation:

corret because vertical Lines intersect at one point after a certain amount of time

The sum of two numbers is 25. The difference between twice the first number and the second number is -10. Find the numbers

Answers

Answer:

15 and 10

Step-by-step explanation:

Let the two numbers be x and y

x+y= 25

2x-2y=-10

Round to nearest degree.
8
х
11

Answers

Answer:

36

Step-by-step explanation:

tan^-1(8/11)=36.027

How do u do this solve for x

Answers

Isolate x by dividing each term by the coefficient

Answer:

The answer is b: 25

Note however that the shape of the diagram does not match the numbers on it.  So either it is poorly drawn, or I am misinterpreting the numbers.  It seems pretty clear though that the image is incorrect, as the two segments both marked as being 25 units long are represented at different lengths.

Step-by-step explanation:

The image here does not fit the numbers.  Note that the bottom triangle has two sides with given lengths of 25 units, but they are drawn as different lengths.

Let's plough on though, and find a better image of what that shape would be.

Starting with the bottom triangle:

Given that the two sides of the bottom triangle are both 25 units in length, we know that it is an isosceles triangle (despite its depiction otherwise).  Because of that, we know that the two bottom angles are equal.  We already know that the top corner is 90°, and that the sum of the angles in a triangle must be 180°  This means that the two bottom angles (again, contrary to how its drawn) are both equal to 45°

Now that we have that information, we can look at the over triangle.  We know that the bottom right corner is 45°, and that the bottom left is 90°.  That tells us that the top angle is also 45°.

With that said, we can redraw the image with the proper proportions.  See the attached image.

That very much simplifies things.  The line separating the triangles bisects the hypotenuse of the larger triangle, meaning that x is also equal to 25.

To be sure of that though, we can prove it another way.  Given that the bottom two corners are both 45, we can use the sine rule to measure x.  The sine rule states that the sine of each angle in a triangle has the same ratio to their opposite sides.  Usually expressed as:

[tex]\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}[/tex]

where a, b and c are the side lengths, and A, B and C are the angles of the corners opposite those sides.

With that we can take the two parts of the overall triangle's hypotenuse, 25 and x, and say that each of those divided by the sine of the angle opposite them is equal to each other:

[tex]\frac{x}{\sin 45} = \frac{25}{\sin 45}[/tex]

This turns out to be very easy to solve, as both sides have the same denominator.  As a result, we can just multiply both sides by sin 45, giving us:

x = 25.

Lol my brain just went blank

Answers

Answer:

is it 3,4

Step-by-step explanation:

sorry if im wrong  i tried.

Wiki
Help I’ll give Brainly est

Answers

Y=2x that’s is the equation

can someone help me do this one problem please like I need help Right now

Answers

find a common denominator
7/12 + 1/12
= 7/12 + 4/12
=11/12

Answer:

x= 11/12

Step-by-step explanation:

you have to make 1/3 equivalent to 7/12 so now you get 4/12+7/12= 11/12



In this triangle, the value of y is:

Answers

Answer:

It's either b or d more likely d though.

Step-by-step explanation:

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