Answer:
66
Step-by-step explanation:
The Empirical Rule states that 68% of data is between 1 standard deviation in a dataset of normal distribution, 95% falls between 2 standard deviations, and 99.7% between 3.
The mean is 450, and one standard deviation is between 450 ± 50 = 400 and 500. Therefore, we can say that 68% of the data falls between 400 and 500 seconds.
The data includes 97 emergencies, so we just need to find 68% of that, which is 0.68*97 = 65.96 (rounding up to 66)
There are 66 emergencies are the response times expected between 400 seconds and 500 seconds.
What is Addition?The process of combining two or more numbers is called the Addition. The 4 main properties of addition are commutative, associative, distributive, and additive identity.
Given that;
mean = 450 sec
standard deviation = 50 sec
Hence, We get;
450-50 =400
450+50=500
Now, In Between 400 sec and 500 sec means one deviation above and one deviation below the mean, and it is 68%.
68% = 0.68
Thus,
0.68 x 97 = 65.96 ≈ 66
Learn more about the addition visit:
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100 POINTS AND BRAINLIEST FOR THIS WHOLE SEGMENT
a) Find zw, Write your answer in both polar form with ∈ [0, 2pi] and in complex form.
b) Find z^10. Write your answer in both polar form with ∈ [0, 2pi] and in complex form.
c) Find z/w. Write your answer in both polar form with ∈ [0, 2pi] and in complex form.
d) Find the three cube roots of z in complex form. Give answers correct to 4 decimal
places.
Answer:
See Below (Boxed Solutions).
Step-by-step explanation:
We are given the two complex numbers:
[tex]\displaystyle z = \sqrt{3} - i\text{ and } w = 6\left(\cos \frac{5\pi}{12} + i\sin \frac{5\pi}{12}\right)[/tex]
First, convert z to polar form. Recall that polar form of a complex number is:
[tex]z=r\left(\cos \theta + i\sin\theta\right)[/tex]
We will first find its modulus r, which is given by:
[tex]\displaystyle r = |z| = \sqrt{a^2+b^2}[/tex]
In this case, a = √3 and b = -1. Thus, the modulus is:
[tex]r = \sqrt{(\sqrt{3})^2 + (-1)^2} = 2[/tex]
Next, find the argument θ in [0, 2π). Recall that:
[tex]\displaystyle \tan \theta = \frac{b}{a}[/tex]
Therefore:
[tex]\displaystyle \theta = \arctan\frac{(-1)}{\sqrt{3}}[/tex]
Evaluate:
[tex]\displaystyle \theta = -\frac{\pi}{6}[/tex]
Since z must be in QIV, using reference angles, the argument will be:
[tex]\displaystyle \theta = \frac{11\pi}{6}[/tex]
Therefore, z in polar form is:
[tex]\displaystyle z=2\left(\cos \frac{11\pi}{6} + i \sin \frac{11\pi}{6}\right)[/tex]
Part A)
Recall that when multiplying two complex numbers z and w:
[tex]zw=r_1\cdot r_2 \left(\cos (\theta _1 + \theta _2) + i\sin(\theta_1 + \theta_2)\right)[/tex]
Therefore:
[tex]\displaystyle zw = (2)(6)\left(\cos\left(\frac{11\pi}{6} + \frac{5\pi}{12}\right) + i\sin\left(\frac{11\pi}{6} + \frac{5\pi}{12}\right)\right)[/tex]
Simplify. Hence, our polar form is:
[tex]\displaystyle\boxed{zw = 12\left(\cos\frac{9\pi}{4} + i\sin \frac{9\pi}{4}\right)}[/tex]
To find the complex form, evaluate:
[tex]\displaystyle zw = 12\cos \frac{9\pi}{4} + i\left(12\sin \frac{9\pi}{4}\right) =\boxed{ 6\sqrt{2} + 6i\sqrt{2}}[/tex]
Part B)
Recall that when raising a complex number to an exponent n:
[tex]\displaystyle z^n = r^n\left(\cos (n\cdot \theta) + i\sin (n\cdot \theta)\right)[/tex]
Therefore:
[tex]\displaystyle z^{10} = r^{10} \left(\cos (10\theta) + i\sin (10\theta)\right)[/tex]
Substitute:
[tex]\displaystyle z^{10} = (2)^{10} \left(\cos \left(10\left(\frac{11\pi}{6}\right)\right) + i\sin \left(10\left(\frac{11\pi}{6}\right)\right)\right)[/tex]
Simplify:
[tex]\displaystyle z^{10} = 1024\left(\cos\frac{55\pi}{3}+i\sin \frac{55\pi}{3}\right)[/tex]Simplify using coterminal angles. Thus, the polar form is:
[tex]\displaystyle \boxed{z^{10} = 1024\left(\cos \frac{\pi}{3} + i\sin \frac{\pi}{3}\right)}[/tex]
And the complex form is:
[tex]\displaystyle z^{10} = 1024\cos \frac{\pi}{3} + i\left(1024\sin \frac{\pi}{3}\right) = \boxed{512+512i\sqrt{3}}[/tex]
Part C)
Recall that:
[tex]\displaystyle \frac{z}{w} = \frac{r_1}{r_2} \left(\cos (\theta_1-\theta_2)+i\sin(\theta_1-\theta_2)\right)[/tex]
Therefore:
[tex]\displaystyle \frac{z}{w} = \frac{(2)}{(6)}\left(\cos \left(\frac{11\pi}{6} - \frac{5\pi}{12}\right) + i \sin \left(\frac{11\pi}{6} - \frac{5\pi}{12}\right)\right)[/tex]
Simplify. Hence, our polar form is:
[tex]\displaystyle\boxed{ \frac{z}{w} = \frac{1}{3} \left(\cos \frac{17\pi}{12} + i \sin \frac{17\pi}{12}\right)}[/tex]
And the complex form is:
[tex]\displaystyle \begin{aligned} \frac{z}{w} &= \frac{1}{3} \cos\frac{5\pi}{12} + i \left(\frac{1}{3} \sin \frac{5\pi}{12}\right)\right)\\ \\ &=\frac{1}{3}\left(\frac{\sqrt{2}-\sqrt{6}}{4}\right) + i\left(\frac{1}{3}\left(- \frac{\sqrt{6} + \sqrt{2}}{4}\right)\right) \\ \\ &= \boxed{\frac{\sqrt{2} - \sqrt{6}}{12} -\frac{\sqrt{6}+\sqrt{2}}{12}i}\end{aligned}[/tex]
Part D)
Let a be a cube root of z. Then by definition:
[tex]\displaystyle a^3 = z = 2\left(\cos \frac{11\pi}{6} + i\sin \frac{11\pi}{6}\right)[/tex]
From the property in Part B, we know that:
[tex]\displaystyle a^3 = r^3\left(\cos (3\theta) + i\sin(3\theta)\right)[/tex]
Therefore:
[tex]\displaystyle r^3\left(\cos (3\theta) + i\sin (3\theta)\right) = 2\left(\cos \frac{11\pi}{6} + i\sin \frac{11\pi}{6}\right)[/tex]
If two complex numbers are equal, their modulus and arguments must be equivalent. Thus:
[tex]\displaystyle r^3 = 2\text{ and } 3\theta = \frac{11\pi}{6}[/tex]
The first equation can be easily solved:
[tex]r=\sqrt[3]{2}[/tex]
For the second equation, 3θ must equal 11π/6 and any other rotation. In other words:
[tex]\displaystyle 3\theta = \frac{11\pi}{6} + 2\pi n\text{ where } n\in \mathbb{Z}[/tex]
Solve for the argument:
[tex]\displaystyle \theta = \frac{11\pi}{18} + \frac{2n\pi}{3} \text{ where } n \in \mathbb{Z}[/tex]
There are three distinct solutions within [0, 2π):
[tex]\displaystyle \theta = \frac{11\pi}{18} , \frac{23\pi}{18}\text{ and } \frac{35\pi}{18}[/tex]
Hence, the three roots are:
[tex]\displaystyle a_1 = \sqrt[3]{2} \left(\cos\frac{11\pi}{18}+ \sin \frac{11\pi}{18}\right) \\ \\ \\ a_2 = \sqrt[3]{2} \left(\cos \frac{23\pi}{18} + i\sin\frac{23\pi}{18}\right) \\ \\ \\ a_3 = \sqrt[3]{2} \left(\cos \frac{35\pi}{18} + i\sin \frac{35\pi}{18}\right)[/tex]
Or, approximately:
[tex]\displaystyle\boxed{ a _ 1\approx -0.4309 + 1.1839i,} \\ \\ \boxed{a_2 \approx -0.8099-0.9652i,} \\ \\ \boxed{a_3\approx 1.2408-0.2188i}[/tex]
What is the slope of a line perpendicular to a line that contains the points (-5, 4) and (-2, 4)?
Select the best answer from the choices provided.
A.
0
B.
no slope
C.
8/3
D.
-3/8
The list below shows the number of books read by students in Aram’s class over the summer. What is the mode of the data
3,6,12,4,3,5,4,8,4,10,4,8,7,5,7
Answer:
the mode is 4 because it appears the most times in the detail set
Answer:
The mode is 3
Step-by-step explanation:
The mode of a set of numbers is whatever number appears the most. So here, you have four 4's, which is the most common number
what is the radius of the semicircle
Which label on the cone below represents the vertex?
D
B
А.
С
ОА
D
Mark this and stum
Save and Exit
The function f(x) = x2 has been translated 9 units up and 4 units to the right to form the function g(x). Which represents g(x)?
g(x) = (x + 9)2 + 4
g(x) = (x + 9)2 − 4
g(x) = (x − 4)2 + 9
g(x) = (x + 4)2 + 9
Answer:
The function that represents g(x) is the third choice: g(x) = (x − 4)^2 + 9
Step-by-step explanation:
The original function has been shifted 9 units up (a vertical transformation). To show a vertical transformation, all we have to do is either add or subtract at the end of the function.
To show a shift upwards, we add the value of change.
To show a shift downwards, we subtract the value of change.
In this case, the original function f(x) = [tex]x^{2}[/tex] was translated 9 units up. Since we shifted up, we simply add 9 to the end of the function: g(x) = [tex]x^{2}[/tex] + 9
The original function has also been shifted 4 units to the right. This is a horizontal transformation. To show a horizontal transformation, we need to either add or subtract within the function (within the parenthesis).
To show a shift to the left, we add the value of change.
To show a shift to the right, we subtract the value of change.
*Notice: Moving left does NOT mean to subtract while moving right does NOT mean to add. The rules above are counterintuitive so pay attention when doing horizontal transformations.
In this case, the original function f(x) = [tex]x^{2}[/tex] was translated 4 units to the right. Since we shifted right, we must subtract 4 units within the function/parenthesis: g(x) = [tex](x-4)^{2}[/tex]
When we combine both vertical and horizontal changes, the only equation that follows these rules is the third choice: g(x) = (x − 4)^2 + 9
Answer: C
Step-by-step explanation:
Which of the following numbers has exactly two significant digits? OA) 3.40 OB) 2.125 OC) 1.0475 OD) 0.00050
Answer:
Here, option (d) has significant digits. hence , option (d) ✓ is correct.I need help I don't understand this at all.
please mark this answer as brainlist
help me plz tyyyyyyyyyy
Answer:
c 6m hope to help
tjabssb
Answer:
3 m
Step-by-step explanation:
because all sides are equal
In the figure, p is parallel to s. Trasnversals t and w intersect at point L.
Statement
What is the missing reason in step 3?
a.) Alternate interior angles along parallel lines are congruent
b.) Alternate exterior angles along parallel lines are congruent
c.) Corresponding angles along parallel lines are congruent
d.) Vertical angles are congruent
Option C
Corresponding angles along parrellel lines are conguerent
Answered by Gauthmath pls mark brainliest and comment thanks and click thanks
Can someone help please
Answer:
[tex]10^{-3}[/tex]
Step-by-step explanation:
Answer:
https://tex.z-dn.net/?f=10%5E%7B-3%7D
Step-by-step explanation:
What is the answer to the question 3x+5x
Answer:
8x
Step-by-step explanation:
=3x+5x
=8x
Find the surface area of the cylinder in terms of T. 9 cm 19 cm Not drawn to scale O 211.5 cm 2 0 382.57 cm 2. O 333 77 cm2 o 504 лcm
Answer:
hey the answer is cylinder= 211.5л!
solve this question :
-10k2+7
Answer:
-10k×2+7
= -20k+7
Step-by-step explanation:
is the answer
Find the value of a. Round
the nearest tenth.
Answer:
side A should be about 44cm
mr.brown can type 80 words in two minutes. how many words can he type in 40 minutes?
Answer:
Step-by-step explanation:
What is the average rate of change of the function over the interval x = 0 to x = 8?
f(x)=2x−1/3x+5
Enter your answer, as a fraction, in the box.
====================================================
Work Shown:
Plug in x = 0
[tex]f(x) = \frac{2x-1}{3x+5}\\\\f(0) = \frac{2*0-1}{3*0+5}\\\\f(0) = \frac{0-1}{0+5}\\\\f(0) = -\frac{1}{5}\\\\[/tex]
Repeat for x = 8
[tex]f(x) = \frac{2x-1}{3x+5}\\\\f(8) = \frac{2*8-1}{3*8+5}\\\\f(8) = \frac{16-1}{24+5}\\\\f(8) = \frac{15}{29}\\\\[/tex]
Now use the average rate of change formula
[tex]m = \frac{f(b)-f(a)}{b-a}\\\\m = \frac{f(8)-f(0)}{8-0}\\\\m = \frac{15/29 - (-1/5)}{8}\\\\m = \frac{15/29 + 1/5}{8}\\\\m = \frac{(15/29)*(5/5) + (1/5)*(29/29)}{8}\\\\m = \frac{75/145 + 29/145}{8}\\\\[/tex]
[tex]m=\frac{104/145}{8}\\\\m = \frac{104}{145} \div \frac{8}{1}\\\\m = \frac{104}{145} \times \frac{1}{8}\\\\m = \frac{104*1}{145*8}\\\\m = \frac{104}{1160}\\\\m = \frac{13}{145}\\\\[/tex]
En su cuenta bancaria, Sally tiene un saldo de -\$200.90−$200.90minus, dollar sign, 200, point, 90. Su amiga Shannon tiene un saldo bancario de -\$240.55−$240.55minus, dollar sign, 240, point, 55. ¿La cuenta bancaria de cuál amiga tiene más deuda
Answer:
Shannon
Step-by-step explanation:
Cuando se habla de lo que uno tiene, podemos usar números positivos.
Por ejemplo:
Pedro tiene 10 manzanas.
Para el caso de deudas, utilizamos números negativos, por ejemplo:
Pedro tiene -10 manzanas
Lo cual significa que Pedro debe 10 manzanas a alguien.
Entonces si le diéramos a Pedro 12 manzanas, el ahora tendría:
-10 + 12 = 2
Pedro tiene 2 manzanas, porque tuvo que entregar 10 de las 12 que le dimos para pagar su deuda.
Ahora vamos a resolver el problema:
La cuenta de Sally tiene un saldo de:
S = -$200.90
El signo negativo quiere decir que Sally tiene una deuda de $200.90
La cuenta de su amiga Shannon tiene un saldo de:
S' = -$240.55
De vuelta, el signo negativo quiere decir que Shannon tiene una deuda de $240.55
Con esto ya podemos concluir que la deuda de Shannon es mayor, por lo tanto Shannon es la que tiene más deuda.
A company distributes candies in bags labeled 23.6 ounces. The local bureau of weights and Measures randomly selects 60 bags of candies and obtain a sample mean of 24 ounces . Assuming that the standard deviation is 3.2. At 0.05 level of significance , test the claim that the bags contain more than 23.6 ounces . what is your conclusion about the claim.
Answer:
The p-value of the test is 0.166 > 0.05, which means that there is not sufficient evidence at the 0.05 significance level to conclude that the bags contain more than 23.6 ounces.
Step-by-step explanation:
A company distributes candies in bags labeled 23.6 ounces. Test if the mean is more than this:
At the null hypothesis, we test if the mean is of 23.6, that is:
[tex]H_0: \mu = 23.6[/tex]
At the alternative hypothesis, we test if the mean is of more than 23.6, that is:
[tex]H_1: \mu > 23.6[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
23.6 is tested at the null hypothesis:
This means that [tex]\mu = 23.6[/tex]
The local bureau of weights and Measures randomly selects 60 bags of candies and obtain a sample mean of 24 ounces. Assuming that the standard deviation is 3.2.
This means that [tex]n = 60, X = 24, \sigma = 3.2[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{24 - 23.6}{\frac{3.2}{\sqrt{60}}}[/tex]
[tex]z = 0.97[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a sample mean above 24, which is 1 subtracted by the p-value of z = 0.97.
Looking at the z-table, z = 0.97 has a p-value of 0.834.
1 - 0.834 = 0.166
The p-value of the test is 0.166 > 0.05, which means that there is not sufficient evidence at the 0.05 significance level to conclude that the bags contain more than 23.6 ounces.
Which series represents this situation? 1+1*7+1*7^ 2 +...1*7^ 6; 1+1*7+1*7^ 2 +...1*7^ 7; 7+1*7+1*7^ 2 +... 1*7^ 6; 7+1*7+1*7^ 2 +...1*7^ 7
Answer:
Step-by-step explanation:
The series is missing from the question. I will answer this question with a general explanation by using the following similar series:
[tex]\sum\limits^6_{n=0} 7^n[/tex]
Required
The series
To do this, we simply replace n with the values
[tex]\sum\limits^6_{n=0}[/tex] means n starts from 0 and ends at 6
[tex]\sum[/tex] means the series is a summation series
So, we have:
[tex]\sum\limits^6_{n=0} 7^n = 7^0 + 7^1 + 7^2 + ...... + 7^6[/tex]
[tex]\sum\limits^6_{n=0} 7^n = 1 + 7 + 7^2 + ...... + 7^6[/tex]
What is the area for the circle?
Answer:
108 squared centimeters
Step-by-step explanation:
Let's exchange π for 3:
area = πr^2
= 3r^2
Now, as you can see, the radius of this circle is 6. Let's plug in the value of r:
area = 3r^2
= 3 · 6^2
Simplify 6^2:
area = 3 · 6^2
= 3 · 36
Multiply 3 by 36:
area = 3 · 36
area = 108
108 squared centimeters
True or false: You would get £3.50 in change from £10.00 if you bought a game for £7.50.
Please help me ASAP!!!!!!!!
Also please accept friend requests. :)
Thanks
Hi there!
»»————- ★ ————-««
I believe your answer is:
False.
»»————- ★ ————-««
Here’s why:
⸻⸻⸻⸻
Change is the difference between how much you pay and the actual price of the item.⸻⸻⸻⸻
[tex]10.00 - 7.50 = 2.50[/tex]
⸻⸻⸻⸻
You would actually receive 2.50.»»————- ★ ————-««
Hope this helps you. I apologize if it’s incorrect.
đồ thị hàm số có bao nhiêu tiệm cận
Answer:
c
Step-by-step explanation:
Can someone please help me find the answer to this question
Answer:
2,-2
you just have to look at the "menu" of choices and determine which one of the choices
fits the question... the f(-4) says you have to see which one of the three
choices has -4 in it ...
the middle one does -4≤x≤1 -4 is for sure in the range
this question #1 answer is "2" because the result is always a 2 for that choice...
the next question put in 3 ... three is greater than 1 (that is the third choice)
so the result is -(3) + 1 = -2
your answers are 2, and -2
Step-by-step explanation:
Anyone any good at math?
Is the relationship shown by the data linear? If so, model the data with an equation
Answer:
yes the x increases by 6 and the y decreases by 3.
y = -1/2x - 7/2
Step-by-step explanation:
find the slope :
(1,-4), (7, -7)
y2- y1 / x2 - x1
substitute those numbers and you get -1/2.
point slope form :
y - y1 = m(x- x1)
y - (-4) = -1/2 ( x - (1))
y+4 = -1/2(x-1)
slope intercept form :
y = -1/2x - 7/2
does this help ?
this is the question. please help me
Answer:
a.) 19.2cm
b.) 0.15375cm
Step-by-step explanation:
Cylinders are similar, so:
h1 / r1 = h2 / r2
8cm / 5cm = h2 / 12cm
h2 = (8cm × 12cm) / 5cm
h2 = 19.2cm
Same for b
32000cm2 / 246cm = 20cm2 / length
length = ((20 × 246) / 32000) cm
length = 0.15375cm
Jonathan has a comic book collection.
He tells you he sold half of them, but then bought 9 more new comics.
After this, Jonathan now has 81 comic books. How many comic books did he have before he sold some? a) Let b = the number of Jonathan had before selling some. Write the equation you would use to solve this problem.
The track team is trying to reduce their time for a relay race. Firstthey reduce their time by 2.1minutes. Then they are able to reduce that time by. If their final time is 3.96 minutes, what was their beginning time?
Answer:
8.16 or 6.06
Step-by-step explanation:
final is 3.96
they reduced their time twice by 2.1min
3.96+2.1+2. 1=8.16
A seat’s position on a Ferris wheel can be modelled by the function y = 18 cos 2.8(x + 1.2) + 21, where y represents the height in feet and x represents the time in minutes. Determine the diameter of the Ferris wheel.
Step-by-step explanation:
A ball is thrown straight up from a rooftop 320 feet high. The formula below describes the ball's height above the ground, h, in feet, t seconds after it was thrown. The ball misses the rooftop on its way down and eventually strikes the ground. How long will it take for the ball to hit the ground? Use this information to provide tick marks with appropriate numbers along the horizontal axis in the figure shown.
h=-16t^2+16t+320
7)On subtracting 8 from x, the result is 2 . Form a linear
equation for the statement.
Answer:
8-x=2
-x=2-8
-x=-6
x=6
if 8 is subtract from 6answer is 2
