Class A has 9 pupils and class B has 24 pupils.
Both classes sit the same maths test.
The mean score for class A is 40.
The mean score for class B is 20.
What is the mean score (rounded to 2 DP) in the maths test across both classes?

Answers

Answer 1

Answer:

mean ≈ 25.45

Step-by-step explanation:

mean is calculated as

mean = [tex]\frac{sum}{count}[/tex]

We require the sum for both classes

class A

mean = [tex]\frac{sum}{9}[/tex] = 40 ( multiply both sides by 9 )

sum = 9 × 40 = 360

class B

mean = [tex]\frac{sum}{24}[/tex] = 20 ( multiply both sides by 24

sum = 24 × 20 = 480

Total sum for both classes = 360 + 480 = 840 , then mean for both classes is

mean = [tex]\frac{840}{33}[/tex] ≈ 25.45 ( to 2 dec. places )


Related Questions

Help I don’t get this

Answers

Answer:

Step-by-step explanation:

5t² + 4t = 5t² + 4 if and only if t=1.

A zero coefficient makes the value of the term equal to zero.

Answer: 5t to the second power and 5t to the second power. I don't know the answer to b.

Step-by-step explanation:

HELP ASAP!!!!!!
Thank you so much

Answers

x_1=-1x2=7y1=1y2=7m:n=3:5

We know

[tex]\boxed{\sf P(x,y)=\left(\dfrac{mx_2+nx_1}{m+n},\dfrac{my_2+ny_1}{m+n}\right)}[/tex]

[tex]\\ \sf\longmapsto p(x,y)=\left(\dfrac{3(7)+5(-1)}{3+5},\dfrac{3(7)+5(1)}{3+5}\right)[/tex]

[tex]\\ \sf\longmapsto p(x,y)=\left(\dfrac{21-5}{8},\dfrac{21+5}{8}\right)[/tex]

[tex]\\ \sf\longmapsto p(x,y)=\left(\dfrac{16}{8},\dfrac{26}{8}\right)[/tex]

[tex]\\ \sf\longmapsto p(x,y)=\left(2,\dfrac{13}{4}\right)[/tex]

m:n=3:5

We know

[tex]\boxed{\sf M(x,y)=\left(\dfrac{mx_2+nx_1}{m+n},\dfrac{my_2+ny_1}{m+n}\right)}[/tex]

[tex]\\ \sf\longmapsto M(x,y)=\left(\dfrac{3(7)+5(-1)}{3+5},\dfrac{3(7)+5(1)}{3+5}\right)[/tex]

[tex]\\ \sf\longmapsto M(x,y)=\left(\dfrac{21-5}{8},\dfrac{21+5}{8}\right)[/tex]

[tex]\\ \sf\longmapsto M(x,y)=\left(\dfrac{16}{8},\dfrac{26}{8}\right)[/tex]

[tex]\\ \sf\longmapsto M(x,y)=\left(2,\dfrac{13}{4}\right)[/tex]

distance between 4, -4 and -7, -4

Answers

Step-by-step explanation:

here's the answer to your question

Answer: Distance = 11

Step-by-step explanation:

Concept:

Here, we need to know the idea of the distance formula.

The distance formula is the formula, which is used to find the distance between any two points.

If you are still confused, please refer to the attachment below for a clear version of the formula.

Solve:

Find the distance between A and B, where:

A (4, -4)B (-7, -4)

[tex]Distance=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

[tex]Distance=\sqrt{(4+7)^2+(-4+4)^2}[/tex]

[tex]Distance=\sqrt{(11)^2+(0)^2}[/tex]

[tex]Distance=\sqrt{121+0}[/tex]

[tex]Distance=\sqrt{121}[/tex]

[tex]Distance=11[/tex]

Hope this helps!! :)

Please let me know if you have any questions

What is the area of the figure

Answers

Answer:

72 in. sq.

Step-by-step explanation:

6 x 6 = 36

6 x 6 = 36 / 2 = 18

6 x 6 = 36 / 2 = 18

18 + 18 + 36 = 72.

Hope this helps!

If there is something wrong just let me know.

72 inches is the answer

URGENT HELP

The gradient of the tangent to the curve y = ax + bx^3 at the point (2, -4) is 6.
Determine the unknowns a and b.
a=?
b=?

Answers

Answer:

a = -6

b = 1

Step-by-step explanation:

The gradient of the tangent to the curve y = ax + bx^3, will be:

dy/dx = a + 3bx²

at (2, -4)

dy/dx = a+3b(2)²

dy/dx = a+12b

Since the gradient at the point is 6, then;

a+12b = 6 ....1

Substitute x = 2 and  y = -4 into the original expression

-4 = 2a + 8b

a + 4b = -2 ...2

a+12b = 6 ....1

Subtract

4b - 12b = -2-6

-8b = -8

b = -8/-8

b = 1

Substitute b = 1 into equation 1

Recall from 1 that a+12b = 6

a+12(1) = 6

a = 6 - 12

a = -6

Hence a = -6, b = 1

Use the procedures developed to find the general solution of the differential equation. (Let x be the independent variable.)

2y''' + 15y'' + 24y' + 11y= 0

Answers

Solution :

Given :

2y''' + 15y'' + 24y' + 11y= 0

Let x = independent variable

[tex](a_0D^n + a_1D^{n-1}+a_2D^{n-2} + ....+ a_n) y) = Q(x)[/tex]  is a differential equation.

If [tex]Q(x) \neq 0[/tex]

It is non homogeneous then,

The general solution  = complementary solution + particular integral

If Q(x) = 0

It is called the homogeneous then the general solution =  complementary solution.

2y''' + 15y'' + 24y' + 11y= 0

[tex]$(2D^3+15D^2+24D+11)y=0$[/tex]

Auxiliary equation,

[tex]$2m^3+15m^2+24m +11 = 0$[/tex]

-1  | 2    15    24     11

    | 0   -2    - 13    -11  

      2    13    11       0

∴ [tex]2m^2+13m+11=0[/tex]

The roots are

[tex]$=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$[/tex]

[tex]$=\frac{-13\pm \sqrt{13^2-4(11)(2)}}{2(2)}$[/tex]

[tex]$=\frac{-13\pm9}{4}$[/tex]

[tex]$=-5.5, -1$[/tex]

So, [tex]m_1, m_2, m_3 = -1, -1, -5.5[/tex]

Then the general solution is :

[tex]$= (c_1+c_2 x)e^{-x} + c_3 \ e^{-5.5x}$[/tex]

 

PLEASE HELP ME AND BE CORRECT

Answers

Answer:

please someone help me with my latest question

Answer:

41 units

Step-by-step explanation:

Its the reflection the length are same

A professor, transferred from Toronto to New York, needs to sell his house in Toronto quickly. Someone has offered to buy his house for $220,000, but the offer expires at the end of the week. The professor does not currently have a better offer but can afford to leave the house on the market for another month. From conversations with his realtor, the professor believes the price he will get by leaving the house on the market for another month is uniformly distributed between $210,000 and $235,000. If he leaves the house on the market for another month, what is the probability that he will get at least $225,000 for the house

Answers

Sorry I’m not sure but others might know

Suppose 5 men and 7 women are on a crowded elevator. At the next floor, four people get off the elevator. Find the probability that three are women.

0.010

0.354

0.424

0.25

Answers

Answer:

B. 0.354

Step-by-step explanation:

Combination of 4 out of 5 + 7 = 12 is:

12C4 = 12!/8!4! = 495

Combination of 1 man and 3 women is:

5C1*7C3 = 5*7!/4!3! = 5*35 = 175

Required probability:

P(3W) = 175/495 ≈ 0.353

Correct choice is B

Which graph shows the solution to the given system of inequalities? [y<6x+1 y<-3.2x-4

Answers

Answer:

VERY NICE RACK U HAVE MAM

Step-by-step explanation:

Answer:

Its a

Step-by-step explanation:

found on another thing and im taking test

the coefficients corresponding to k=0,1,2,5 in the expression (x+y)^5 are

Answers

Answer:

Step-by-step explanation: you got trolded

Work out 45% of $200.00

Answers

Answer:

If you are using a calculator, simply enter 45÷100×200 which will give you 90 as the answer.

Mark me brainliest plz.

First you change 45% to decimal form (move the decimal two places to the left) which gives .45

Then, you multiply .45 x $200.00

Your answer is $90

Can someone help me with this problem

Answers

Answer:

3/11

Step-by-step explanation:

the answer is 9/110 zzzz

What is a1
of the arithmetic sequence for which a3=126
and a64=3,725
a
64
=
3
,
725
?

Answers

In an arithmetic sequence, every pair of consecutive terms differs by a fixed number c, so that the n-th term [tex]a_n[/tex] is given recursively by

[tex]a_n=a_{n-1}+c[/tex]

Then for n ≥ 2, we have

[tex]a_2=a_1+c[/tex]

[tex]a_3=a_2+c = (a_1+c)+c = a_1 + 2c[/tex]

[tex]a_4=a_3+c = (a_1 + 2c) + c = a_1 + 3c[/tex]

and so on, up to

[tex]a_n=a_1+(n-1)c[/tex]

Given that [tex]a_3=126[/tex] and [tex]a_{64}=3725[/tex], we can solve for [tex]a_1[/tex]:

[tex]\begin{cases}a_1+2c=126\\a_1+63c=3725\end{cases}[/tex]

[tex]\implies(a_1+63c)-(a_1+2c)=3725-126[/tex]

[tex]\implies 61c = 3599[/tex]

[tex]\implies c=59[/tex]

[tex]\implies a_1+2\times59=126[/tex]

[tex]\implies a_1+118 = 126[/tex]

[tex]\implies \boxed{a_1=8}[/tex]

Question 7 of 13
Find the solution to the system of equations,
5x - 3y - Z= 6
-4x + 5y + z = 6
Х
+ 3z = 10

Answers

Answer:

D. x = 4,  y = 4, z = 2

Step-by-step explanation

Plugged in given answers as trying to substitute is impossible, already tried all combinations

https://www.drfrostmaths.com/util-generatekeyskillpic.php?name=AnglePoint4&width=400&params=%5B61%2C0%2C%22y%22%2C4%5D

Answers

Answer:

Complementary angle

<y+61° =90°

<y = 90°- 61°

<y =29°

I Hope this helps.

Find the x- and y-intercepts of the following line: 4x − 3y = 12

Answers

Answer:

x-intercept: (3,0)

y-intercept: (0,-4)

Step-by-step explanation:

To find the x and y-intercepts, we first need to understand what they are. X and y-intercepts are points on the line that passes through the x-axis and y-axis. When a point is an x-intercept, it passes through the x-axis. This means the x-coordinate is an integer, while the y-coordinate is always 0. This can be denoted by (x,0). When a point is a y-intercept, it passes through the y-axis. This means the y-coordinate is an integer, while the x-coordinate is always 0. This can be denoted by (0,y).

Now that we know what x and y-intercepts are, we can plug in x=0 and y=0 to find the intercepts.

x-intercept

4x-3y=12            [plug in y=0]

4x-3(0)=12          [multiply]

4x-0=12              [add both sides by 0]

4x=12                 [divide both sides by 4]

x=3

---------------------------------------------------------------------------------------------------------

y-intercept

4x-3y=12            [plug in x=0]

4(0)-3y=12         [multiply]

0-3y=12             [subtract both sides by 0]

-3y=12               [divide both sides by -3]

y=-4

Therefore, the x-intercept is (3,0) and y-intercept is (0,-4).

the line that passes through the point (-4, 2) and has a
What is the equation of
slope of
2?

Answers

Answer:

y = 2x + 10

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 )

Here m = 2 , then

y = 2x + c ← is the partial equation

To find c substitute (- 4, 2 ) into the partial equation

2 = - 8 + c ⇒ c = 2 + 8 = 10

y = 2x + 10 ← equation of line

А _______ equation can be written in the form ax2 + bx+c=0 where a, b, and c are real numbers, and a is a nonzero number.

Fill in the blank.

A) quadratic
B) quartic
C) linear
D) cubic

Wrong answers WILL be reported. Thanks!

Answers

Answer:

A) quadratic

Step-by-step explanation:

ax2 + bx+c=0

Since the highest power of the equation is 2

A) quadratic -2

B) quartic- 4

C) linear- 1

D) cubic-3

A) quadratic because the highest power of the equation is 2

What is the best interpretation of the y-intercept of the line

Answers

Answer:

vertical line

Step-by-step explanation:

because horizontal means horizon which goes left to right across a board

Hi there!

The y-intercept of a line represents its initial value. On a graph, the y-intercept would represent the value of y when the line crosses the y-axis.

For example, if an equation were to model the amount of money someone had in their bank account overtime starting from the day they opened their account, the y-intercept would represent the original amount of money they had.

I hope this helps!

Open the graphing tool one last time. Compare the graphs of y=log (x-k) and y=log x+k in relation to their domain, range, and asymptotes. Describe what you see.

Answers

Answer:

sorry I don't know the answer

Answer:

For the equation y=log(x-k), the domain depends on the value of K. Sliding K moves the left bound of the domain interval. The range and the right end behavior stay the same. For the equation y=log x+k, the domain is fixed, starting at an x-value of 0. The vertical asymptote is also fixed. The range of the equation depends on K.

Step-by-step explanation:

What is the numerical coefficient of the first term

Answers

Answer:

the number before the first variable (first term)

Step-by-step explanation:

this appears to be an incomplete question. The numerical coefficient of a term is the number before the variable.

the constant is the number without a variable.

The constant number without the verbal?

3w2 – 21w = 0

Need some help.

Answers

Answer:

The solutions are w=0 ,7

Step-by-step explanation:

3w^2 – 21w = 0

Factor out 3w

3w(w-7) =0

Using the zero product property

3w=0  w-7=0

w =0    w=7

The solutions are w=0 ,7

a gym class has 10 boys and 12 girls. how many ways can a team of 6 be selected if the team must have the same number of boys and girls

Answers

Answer:

The number of ways of selecting the team is 26,400 ways.

Step-by-step explanation:

Given;

total number boys in the gym, b = 10 boys

total number of girls in the gym, g = 12 girls

number of team to be selected, n = 6

If there must equal number of boys and girls in the team, then the team must consist of 3 boys and 3 girls.

Number of ways of choosing 3 boys from the total of 10 = [tex]10_C_3[/tex]

Number of ways of choosing 3 girls from a total of 12 = [tex]12_C_3[/tex]

The number of ways of combining the two possibilities;

[tex]n = 10_C_3 \times 12_C_3\\\\n = \frac{10!}{7!3!} \ \times \ \frac{12!}{9!3!} \\\\n = \frac{10\times 9 \times 8}{3\times 2} \ \times \ \frac{12\times 11 \times 10}{3\times 2} \\\\n = 120 \times 220\\\\n = 26,400 \ ways[/tex]

Therefore, the number of ways of selecting the team is 26,400 ways.

The sum of two binomials is 12x2 − 5x. If one of the binomials is x2 − 2x, the other binomial is:

1. 11x2 − 7x.
2. 12x2 − 3x.
3. 11x2 − 3x.
4. None of these choices are correct.

Answers

Answer:

C. 11x² - 3x

Step-by-step explanation:

(12x² - 5x) - (x² - 2x)

12x² - 5x - x² + 2x

12x - x² - 5x + 2x

11x² - 3x

Select the correct answer. Which graph represents this inequality? y ≥ 4x − 3

Answers

Step-by-step explanation:

You didn't put the graph, but you can compare between your graphs and the picture.

Brainliest please

The graph that represents this inequality y ≥ 4x − 3 is attached below.

What is a solution set to an inequality or an equation?

If the equation or inequality contains variable terms, then there might be some values of those variables for which that equation or inequality might be true. Such values are called solution to that equation or inequality. Set of such values is called solution set to the considered equation or inequality.

We are given that the inequality is;

y ≥ 4x − 3

The slope of the inequality is 4.

The equation of the red line is y = 4x − 3  

The shading is above the line and the line is solid, that means  y is greater than or equal 4x − 3

The graph of this inequality y ≥ 4x − 3 is attached below.

Learn more about inequalities here:

https://brainly.com/question/27425770

#SPJ2

Which diagram best shows how fraction bars can be used to evaluate One-half divided by one-fourth? A fraction bar labeled 1. Under the 1 are 2 boxes containing one-half. Under the 2 boxes are 4 boxes containing one-fourth. 2 one-fourths are circled. A fraction bar labeled one-fourth. Under the one-fourth are 2 boxes containing one-half. Under the 2 boxes are 4 boxes containing 1. 2 boxes containing 1 are circled. A fraction bar labeled 1. Under the 1 are 4 boxes containing one-fourth. Under the 4 boxes are 8 boxes containing one-half. One box containing one-half is circled. A fraction bar labeled 1. Under the 1 are 4 boxes containing one-fourth. Under the 4 boxes are 2 boxes containing one-half. One box containing one-half is circled.

Answers

Answer:

Step-by-step explanation:

The description is too ambiguous to reconstruct the diagram. You need to post the actual diagram.

That diagram is just one way to view division by a fraction. An easier way: DIVIDING by a fraction is the same as MULTIPLYING by the upside-down fraction. For example,

(1/2) ÷ (1/4) = (1/2) × (4/1) = 2

That doesn’t help you answer this particular question, though.

Answer:

C

Step-by-step explanation:

Find the volume of a cone whose height is 12 and whose radius is 4. Use 3.14 for Pi and round your final answer to one decimal place.

Answers

Answer:

201.088 cubic units

Step-by-step explanation:

Given data

height= 12 units

radius= 4 units

The expression for the volume of a cone is given as

Volume = 1/3*πr^2h

Substitute the given data to find the volume of the cone

Volunme= 1/3* 3.142* 4^2* 12

Volume = 1/3* 3.142* 16*12

Volume= 1/3* 603.264

Volume= 201.088 cubic units

6
1
10 points
Find the probability that a randomly selected person's birthday is not in May. Ignore leap years.
31
334
31
365
334
365
11
2
3
12
Previous

Answers

Answer:

c. [tex]\frac{334}{365}[/tex]

Step-by-step explanation:

May has 31 days and a normal year is 365 days, so the probability is [tex]\frac{31}{365}[/tex]

The probability that isn't in May is: 1 - [tex]\frac{31}{365}[/tex] = [tex]\frac{334}{365}[/tex]

The thicknesses of 81 randomly selected aluminum sheets were found to have a variance of 3.23. Construct the 98% confidence interval for the population variance of the thicknesses of all aluminum sheets in this factory. Round your answers to two decimal places

Answers

Answer:

The confidence interval for the population variance of the thicknesses of all aluminum sheets in this factory is Lower limit = 2.30, Upper limit = 4.83.

Step-by-step explanation:

The confidence interval for population variance is given as below:

[tex][(n - 1)\times S^{2} / X^{2} \alpha/2, n-1 ] < \alpha < [(n- 1)\times S^{2} / X^{2} 1- \alpha/2, n- 1 ][/tex]

We are given

Confidence level = 98%

Sample size = n = 81

Degrees of freedom = n – 1 = 80

Sample Variance = S^2 = 3.23

[tex]X^{2}_{[\alpha/2, n - 1]} = 112.3288\\\X^{2} _{1 -\alpha/2,n- 1} = 53.5401[/tex]

(By using chi-square table)

[(n – 1)*S^2 / X^2 α/2, n– 1 ] < σ^2 < [(n – 1)*S^2 / X^2 1 -α/2, n– 1 ]

[(81 – 1)* 3.23 / 112.3288] < σ^2 < [(81 – 1)* 3.23/ 53.5401]

2.3004 < σ^2 < 4.8263

Lower limit = 2.30

Upper limit = 4.83.

Other Questions
Why did the North and South go to war?The South fought to , while the North fought to . You should spend about 20 minutes on this task. You received an eman from your fa She asked you for some information about Tet holiday. Read part of her smaid below.My family is going to celebrate the New Year's Day next week and we are all excited about it. Tell me about the Tet holiday in your country. What do people do? What kinds of special food do you eat? What do you feel on this occasion?Write an email responding to Jane. You should write at least 120 words. You do not need to include your name or addresses. Your response will be evaluated in terms of Tank Fulfillment Organ Vocabulary and Grammar,from your English friend, Sam Identify at least 2 circumstances in which you believe it would be better to request a meeting to discuss an issue rather than an email Which of the following lines is parallel to the liney = 1/2x -6Select one:a) y=-1/2x-6b) y=2x+1c) y=-1/2x+5d) y=1/2x-3 find two factors of the first number such that their product is the first number and their sum is the second number.70,17 Do you agree or disagree that the trouble with welfare is that people get too comfortable and don't want to go back to work defects rewritten approrpiate scale of measurement? If f(x) = x23x+1x1find f(-1) and f(-3) on the map above.In the United States, large quantities of oil and natural gas can be found in regionA.B. 2C. 3D. 4Please select the best answer from the choices providedDMadinis accesoSave and ExitNextSub Economists can use new technology to Two boys together have $12. One of them has $10 more than the other. How much money does each of them have It has been three weeks since Mr. Garrisons wife died. He blames himself for her death. If only he had insisted that she see the doctor when she started feeling weak and tired! Which term BEST describes what Mr. Garrison is experiencing? a. abnormal grievingb. healthy grievingc. acute mourningd. bereavement What is the value of the first term in the following arithmetic sequence?-9, -2, 5, 12, ...-979-7 PLEASE HELP (ILL GIVE BRAINLIEST)Please Help I need Help Please Help I need someone to do this Help anyone can help me do this question,I will mark brainlest. a. What is 46.7% of 4/5? Pierre has had a difficult childhood. He fled a civil war in his home country before settling in France, and has a unique perspective about the importance of his extended family. A psychologist working with Pierre should be aware of his situation and background in order to provide the best possible treatment. This awareness is known as The graph f(x) shown below has the same shape as the graph of g(x)=x^2 which of the following is the equation of f(x) Pls help im on a timerThe most important development of the New Stone Age was the ability to communicatePlease select the best answer from the choices providedTrue false first answer gets marked brainliest!! QUESTION 2In A XYZ, X = 18 cm, y = 14 cm, and z= 17 cm.Determine the measure of Z to the nearest degree.a. 66b. 63c. 57d. 60