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4 years ago

The ratio of bous to girls in the school is 1 to 4. If there are 20 girls, how many boys are there?

Mathematics

2 answers:

hjlf4 years ago

7 0

There is 5 boys since there is 20 girls

anyanavicka [17]4 years ago

6 0

if there's 1 boy to every 4 girls, there's going to be 5 boys for every 20 girls

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Write an expression to represent: Six less than the product of four and a number x

Nutka1998 [239]

Answer:

6-4x

Step-by-step explanation:

3 0

3 years ago

In a recent study on world happiness, participants were asked to evaluate their current lives on a scale from 0 to 10, where 0

Zigmanuir [339]

Answer:

a) 8.2962

b) 6.3956

c) 3.845

Step-by-step explanation:

Z-score:

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

$\mu = 5.6, \sigma = 2.6$

(a) What response represents the 85th percentile? 

This is X when Z has a pvalue of 0.85. So X when Z = 1.037.

$Z = \frac{X - \mu}{\sigma}$

$1.037 = \frac{X - 5.6}{2.6}$

$X - 5.6 = 2.6*1.037$

$X = 8.2962$

(b) What response represents the 62nd percentile?

This is X when Z has a pvalue of 0.62. So X when Z = 0.306.

$Z = \frac{X - \mu}{\sigma}$

$0.306 = \frac{X - 5.6}{2.6}$

$X - 5.6 = 2.6*0.306$

$X = 6.3956$

(c) What response represents the first quartile?

The first quartile is the 100/4 = 25th percentile. So this is X when Z has a pvalue of 0.25, so X when Z = -0.675.

$Z = \frac{X - \mu}{\sigma}$

$-0.675 = \frac{X - 5.6}{2.6}$

$X - 5.6 = 2.6*(-0.675)$

$X = 3.845$

3 0

3 years ago

Can anyone do 4,5 and 6 for me plz

cricket20 [7]

For question 4, $sinA =\frac{a}{c}, cosA= \frac{b}{c}, tan B = \frac{b}{a}, sin J = \frac{j}{l}, cosK = \frac{j}{l}, tanK = \frac{k}{j}.$

Question 5. Option a and question 6. Option j

Step-by-step explanation:

Step 1:

The three basic formula needed to solve these questions are:

$sin\theta = \frac{oppositeside}{hypotenuse} , cos\theta = \frac{adjacentside}{hypotenuse}, tan\theta= \frac{opposite side}{adjacent side}.$

Step 2:

Using the above formula, we solve the following values

$sinA = \frac{oppositeside}{hypotenuse}$ $=\frac{a}{c}.$

$cosA = \frac{adjacentside}{hypotenuse}$ $= \frac{b}{c}.$

$tanB= \frac{opposite side}{adjacent side}$ $= \frac{b}{a}.$

$sinJ = \frac{oppositeside}{hypotenuse}$ $= \frac{j}{l}.$

$cosK = \frac{adjacentside}{hypotenuse}$ $= \frac{j}{l}.$

$tanK= \frac{opposite side}{adjacent side}$ $= \frac{k}{j}.$

Step 3:

For question 5, The triangle's angle = 23°, opposite side = BC inches and hypotenuse = 4 inches.

$sin\theta= \frac{opposite side}{hypotenuse}. sin 23^{\circ}= \frac{BC}{4}, sin23^{\circ} = 0.3907,BC = (0.3907)(4) = 1.5628.$

SO BC is 1.5628 inches, rounding this off to the nearest tenth, we get BC = 1.6 inches which is option a.

Step 4:

For question 6, The triangle's angle = 50°, opposite side = QR m the adjacent side = 8.1 m.

$tan\theta= \frac{opposite side}{adjacentside}. tan 50^{\circ}=\frac{QR}{8.1}, tan50^{\circ} = 1.1917,QR = (1.1917)(8.1) = 9.65277$

SO QR is 9.65277 meters, rounding this off to the nearest tenth, we get QR = 9.7 inches which is option j.

7 0

3 years ago

Select all the expressions that are equivalent to - 2/5 (15-20d + 5c).

Nostrana [21]

One of them is -6+8d-2c

4 0

3 years ago

What is the sum of the 2nd square number and the 5th cube number

lisabon 2012 [21]

Answer:

129

Step-by-step explanation:

4+125=129

7 0

3 years ago

Read 2 more answers