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3 years ago

There are 3 boys for every 4 girls in a classroom. If there are 9 boys, how many girls are in the classroom?

Mathematics

2 answers:

Nady [450]3 years ago

7 0

Answer:

12 girls are in the classroom.

Step-by-step explanation:

We find out that the ratio is 3:4 based upon the question.

If there's 9 boys then the ratio is incomplete however you just need complete it based on the information given.

So, 3:4

9:?

9 / 3 = 3

4 x 3 - 12 girls

Thus, there being 12 girls in the classroom.

To check:

9:12;

9 / 3 = 3

12 / = 4

So the ratio still ends up being 3:4 therefore 9:12 is equivalent and correct!

Hope this helped! Have a great day or night wherever you are, stay safe!

Sholpan [36]3 years ago

4 0

Answer:

36 girls in the class

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A certain standardized test's math scores have a bell-shaped distribution with a mean of 530 and a standard deviation of 119. Co

kumpel [21]

Answer:

a) 68.2%

b) 31.8%

c) 2.3%

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 530

Standard Deviation, σ = 119

We are given that the distribution of math scores is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(test scores is between 411 and 649)

$P(411 \leq x \leq 649)\\\\= P(\displaystyle\frac{411 - 530}{119} \leq z \leq \displaystyle\frac{649-530}{119})\\\\= P(-1 \leq z \leq 1)\\\\= P(z \leq 1) - P(z < -1)\\= 0.841 - 0.159 = 0.682 = 68.2\%$

b) P(scores is less than 411 or greater than 649)

$P(x < 411 < x, x > 649)\\=1 = P(411 \leq x \leq 649)\\=1 - 0.682\\=0.318 = 31.8\%$

c) P(score greater than 768)

P(x > 768)

$P( x > 768) = P( z > \displaystyle\frac{768 - 530}{119}) = P(z > 2)$

$= 1 - P(z \leq 2)$

Calculation the value from standard normal z table, we have,

$P(x > 768) = 1 -0.977 = 0.023 = 2.3\%$

5 0

3 years ago

Monica is mixing some custom-colored paint for her house. The color she wants requires 3⁄4 ounce of blue dye and 2⁄3 of an ounce

Genrish500 [490]

Ounce of blue dye mixed with one gallon of white paint base = 3/4

Ounce of blue dye mixed with eight gallons of white paint base = $\frac{3}{4} (8)$

= 3 × 2

Ounce of pink dye mixed with one gallon of white paint base = 2/3

Ounce of pink dye mixed with eight gallons of white paint base = $\frac{2}{3} (8)$

= 16/3

= 5.3

Hence, 6 ounce of blue dye and 5.3 ounce of pink dye are needed to mix with 8 gallons of paint.

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3 years ago

Read 2 more answers

What is the answer is of it tell me fast

s344n2d4d5 [400]

Answer :

Given -

Books read by aya = 5
Total number of books read by them = 14

To find -

How many books does luka reads.

Solution -

Here, total number of books is 14 and books read ny aya is 5 . To find the luka reads We'll subtract total number of books read by them from books read by aya.