If you double a number and then add 28, you get four ninths of the original number. What is the original number?

Need help pls<br>thank you in advance

ira [324]

Answer:

<u />

$\textsf{Mean}\:\overline{X}=\sf \dfrac{\textsf{sum of all the data values}}{\textsf{total number of data values}}$

$\implies \sf Mean\:(Nilo)=\dfrac{5+6+14+15}{4}=\dfrac{40}{4}=10$

$\implies \sf Mean\:(Lisa)=\dfrac{8+9+11+12}{4}=\dfrac{40}{4}=10$

<h3><u>Standard Deviation</u></h3>

$\displaystyle \textsf{Standard Deviation }s=\sqrt{\dfrac{\sum X^2-\dfrac{(\sum X)^2}{n}}{n-1}}$

$\begin{aligned}\displaystyle \textsf{Standard Deviation (Nilo)} & =\sqrt{\dfrac{(5^2+6^2+14^2+15^2)-\dfrac{(5+6+14+15)^2}{4}}{4-1}}\\\\& = \sqrt{\dfrac{482-\dfrac{40^2}{4}}{3}}\\\\& = \sqrt{\dfrac{82}{3}}\\\\& = 5.23\end{aligned}$

$\begin{aligned}\displaystyle \textsf{Standard Deviation (Lisa)} & =\sqrt{\dfrac{(8^2+9^2+11^2+12^2)-\dfrac{(8+9+11+12)^2}{4}}{4-1}}\\\\& = \sqrt{\dfrac{410-\dfrac{40^2}{4}}{3}}\\\\& = \sqrt{\dfrac{10}{3}}\\\\& = 1.83\end{aligned}$

<h3><u>Summary</u></h3>

Nilo has a mean score of 10 and a standard deviation of 5.23.

Lisa has a mean score of 10 and a standard deviation of 1.83.

The <u>mean</u> scores are the <u>same</u>.

Nilo's standard deviation is higher than Lisa's. Therefore, Nilo's test scores are more <u>spread out</u> that Lisa's, which means Lisa's test scores are more <u>consistent</u>.

5 0

2 years ago

Just answer no need to explain.

Bogdan [553]

Shifting to left mean adding the number from each occurrence of x from the given function.

So, shifting x³ , 3 units to left will result in:

f(x) = (x + 3)³

Shifting down means subtracting the number from the function value.

So, shifting 2 units down will result in:

f(x) = (x + 3)³ - 2

Therefore, option A is the correct graph

8 0

3 years ago

Read 2 more answers

Emma is standing 10 feet away from the base of a tree and tries to measure the angle of elevation to the top. She is unable to g

Vaselesa [24]

The complete question in the attached figure

step 1
find the tree height for an angle of elevation of 55°<span>
tan 55</span>°=opposite side angle 55°/adjacent side angle 55°
opposite side angle 55°=the tree height h1
adjacent side angle 55°=10 ft
so
tan 55°=h/10-------> h=10*tan 55°-----> h=14.28 ft

step 2
find the tree height for an angle of elevation of 75°
tan 75°=opposite side angle 75°/adjacent side angle 75°
opposite side angle 75°=the tree height h2
adjacent side angle 75°=10 ft
so
tan 75°=h2/10-------> h2=10*tan 75°-----> h2=37.32 ft

therefore

<span>the height of the tree is within the range [14.26,37.32]
</span>
Part 1) 4.2 ft

<span>the value is not in the interval [14.26,37.32]
therefore
it is </span>Not Reasonable

Part 2) 14.7 ft

the value is in the interval [14.26,37.32]
therefore
it is Reasonable

Part 3) 24.4 ft

the value is in the interval [14.26,37.32]
therefore
it is Reasonable

Part 4) 33.9 ft

the value is in the interval [14.26,37.32]
therefore
it is Reasonable

Part 5) 39.1ft

the value is not in the interval [14.26,37.32]
therefore
it is Not Reasonable

Part 6) 58.7 ft

the value is not in the interval [14.26,37.32]
therefore
it is Not Reasonable