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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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Answer:

Not enough information. For this to be SAS, the single tick mark would need to be located on the line CB and ED.

Step-by-step explanation:


6 0
3 years ago
6 3/8 divided by 2 1/8
wariber [46]

Answer:

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6 0
4 years ago
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An aluminum can is a right cylinder. Find the amount of paper needed for the can's label and the total
Rina8888 [55]

Answer:

Label: About 527.9 square centimeters

Aluminum: About 835.7 square centimeters

Step-by-step explanation:

Amount of paper needed for the label:

You can imagine taking off the label and unrolling it, forming a rectangle. The height of this rectangle will be the height of the cylinder, while the length of the rectangle will be the circumference of the cylinder. Therefore, the area of that rectangle will be 2\pi r h= 2 \cdot \pi \cdot 7 \cdot 12\approx 527.9.

Amount of aluminum needed for the can:

This time, you need to add in the top and bottom of the can as well, which each have area \pi r^2. Together, they have area 2\pi r^2=2\cdot \pi \cdot 7^2\approx 307.9. Adding this to the area of the sides, you get a total of about 835.7 square centimeters.

Hope this helps!

6 0
3 years ago
The advertising department of a nationally circulated magazine wishes to estimate the mean age of its subscribers within 0.5 yea
zhenek [66]

Answer: Option 'd' is correct.

Step-by-step explanation:

Since we have given that

Margin of error = 0.5 years

Standard deviation = 5

At 90% confidence, z = 1.645

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5 0
3 years ago
What does 8.4 10^5-7.7 10^4 equal?
Alex

Answer:

\huge\boxed{763,000=7.63\cdot10^5}

Step-by-step explanation:

\bold{METHOD\ 1:}\\\\8.4\cdot10^5-7.7\cdot10^4=8.4\cdot100,000-7.7\cdot10,000\\\\=840,000-77,000=763,000\\\\\bold{METHOD\ 2:}\\\\8.4\cdot10^5-7.7\cdot10^4=8.4\cdot10^{1+4}-7.7\cdot10^4\qquad\text{use}\ a^n\cdot a^m=a^{n+m}\\\\=8.4\cdot10^1\cdot10^4-7.7\cdot10^4=84\cdot10^4-7.7\cdot10^4\\\\\text{use the distributive property}:\qquad a(b+c)=ab+ac\\\\=(84-7.7)\cdot10^4=76.3\cdot10^4=7\underbrace{.63}_{\leftarrow1}\cdot10^{4+1}=7.63\cdot10^5

5 0
3 years ago
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