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andriy [413]
3 years ago
10

No need of a answer anymore.

Mathematics
1 answer:
Rom4ik [11]3 years ago
5 0

Answer:

mean score of class B = 1778/25 = 71.12

Step-by-step explanation:

This was your question : Class A has 12 pupils and class B has 25 pupils. Both classes sit the same maths test. The mean score for class A is 80. The mean score for both classes is 74. What is the mean score (rounded to 2 DP) in the maths test for class B?

mean of class A = Σfx/Σf

mean of class A =  80

Σfx = 80 × 12 = 960

Mean score for both classes = 74

where

b = Σfx  of class B

960 + b/37 = 74

cross multiply

960 + b = 2738

b = 2738 - 960

b = 1778

mean score of class B = Σfx/Σf

Σfx = 1778

Σf = 25

Therefore,

1778/25 = 71.12

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VARVARA [1.3K]

Answer:

x= -6 | I only have an answer for #7 but you should use a website called Symbolab :)

Step-by-step explanation:

x+16+x+12+2x+15=19

<em>group like terms: </em>

4x+43=19

<em>subtract 43 from both sides:</em>

4x+43=19

   -43 -43

<em>simplify</em>:

4x=-24

<em>divided both sides by 4:</em>

x=-6

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2 years ago
it is recommended that one fire extinguisher be available for every 6000 square feet in a building. write and solve an equation
Leviafan [203]
135000/6000=X
22.5=X

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3 years ago
HELP HURRYYY!!! I DONT KNOW
Anettt [7]

Answer:

it would be A. it would be A because on the x coordinate would be placed like (x, y) 4 is negative and 6 is positive, hence (-4, 6)

Step-by-step explanation:

<em>can i have brainliest?</em>

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2 years ago
There are 30 students in a class, including 16 boys. Write each ratio. A. Girls to boys. B. Boys to Girls. C. Girls to all stude
Fudgin [204]
30 students in a class, and 16 boys and 14 girls.

A ratio compares two quantities. 

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Read 2 more answers
Will give BRAINLEST :)
DiKsa [7]

Answer:

A

Step-by-step explanation:

This explanation mostly depends on what you're learning right now. The first way would be to convert this matrix to a system of equations like this.

g + t + k = 90

g + 2t - k = 55

-g - t + 3k = 30

Then you solve using normal methods of substitution or elimination. It seems to me that elimination is the quickest method.

g + t + k = 90

-g - t + 3k = 30

____________

0 + 0 + 4k = 120

4k = 120

k = 30

No you can plug this into the first two equations

g + t + (30) = 90

g + t = 60

and

g + 2t - (30) = 55

g + 2t = 85

now use elimination again by multiplying the first equation by -1

g + 2t = 85

-g - t = -60

_________

0 + t = 25

t = 25

Now plug those both back into one of the equations. I'll just do the first one.

g + (25) + (30) = 90

g = 35

Therefore, we know that Ted spent the least amount of time on the computer.

The second method is using matrix reduction and getting the matrix in the row echelon form, therefore solving using the gauss jordan method. If you would like me to go through this instead, please leave a comment.

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