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3 years ago

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E The shadow of the moon during a solar eclipse travels 2300 miles in 1 hour. In the first 20 minutes, the shadow traveled $766\

frac{2}{3}$ miles. How long does it take for the shadow to travel 1150 miles?

1 answer:

Reika [66]3 years ago

8 0

Answer:

c3po 1049596979ebsbsnwnanxbxjxo o ocjsbzbxbbxh h h.

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The manager of a fleet of automobiles is testing two brands of radial tires and assigns one tire of each brand at random to the

Darya [45]

Answer:

Brand 1 Brand 2 Difference

37734 35202 2532

45299 41635 3664

36240 35500 740

32100 31950 150

37210 38015 −805

48360 47800 560

38200 37810 390

33500 33215 285

Sum of difference = 2532+ 3664+740+150 −805+ 560 +390 +285 = 7516

Mean = $d=\frac{7516}{8}$

Mean = $d=939.5$

a) d= 939.5

$\text{Sample Standard deviation, s} = \sqrt{\dfrac{(x-\bar{x})^2}{n-1}}$

$=\sqrt{\dfrac{(2532-939.5)^2+(3664-939.5)^2+(740-939.5)^2 ...+(285-939.5)^2}{8-1}}$

=1441.21

b)SD= 1441.21

c)Calculate a 99% two-sided confidence interval on the difference in mean life.

confidence level =99%

significance level =α= 0.01

Degree of freedom = n-1 = 8-1 =7

So, $t_{\frac{\alpha}{2}}=3.499$

Formula for confidence interval $= \left( \bar{X} \pm t_{\frac{\alpha}{2}} \times \frac{s}{\sqrt{n}} \right)$

Substitute the values

confidence interval $= 939.5 \pm 3.499 \times \frac{1441.21}{\sqrt{8}} \right)$

confidence interval $= 939.5 - 3.499 \times \frac{1441.21}{\sqrt{8}} \right)$ to $= 939.5 + 3.499 \times \frac{1441.21}{\sqrt{8}} \right)$

Confidence interval $−843.396\$ to $2722.396$

8 0

3 years ago

Let a = 2i + 3, b= i – 1, and c= -3i + 2. Which expression is equivalent to a -b- c?A. –2i +4B. 4i + 2C. 4i + 4D. -2i + 2

34kurt

Given:

$\begin{gathered} a=2i+3 \\ b=i-1 \\ c=-3i+2 \end{gathered}$

You know that:

$a-b-c=(2i+3)-(i-1)-(-3i+2)$

In order to solve the operation, you can follow these steps:

1. Distribute the negative signs. Remember the Sign Rules for Multiplication:

$\begin{gathered} +\cdot+=+ \\ -\cdot-=+ \\ +\cdot-=- \\ -\cdot+=- \end{gathered}$

Then:

$=2i+3-i+1+3i-2$

2. Combine the like terms (add the Real Parts and add the Imaginary Parts):

$=4i+2$

Hence, the answer is: Option B.

3 0

2 years ago

The perimeter of a rectangle is 300 feet. The width of the rectangle is 10 feet more than the length. What is the width of the r

gavmur [86]

300 = 2(x + x + 10)
300 = 2(2x +10)
300 = 4x + 20
4x = 280
x = 70
x + 10 = 80
width = 80ft
answer <span>D) 80 feet</span>

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3 years ago

Which decimal represents the fraction of cats in this group that are black?

Lubov Fominskaja [6]

Since there are 8 total, and 4 is the amount to find as a fraction, we simply divide 4 by 8 to get 4/8

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4 years ago

can you guys solve this please a movie theaters has 4 groups of seats the largest group of seats in the middle has 20 rows with

Hatshy [7]

Answer:

Step-by-step explanation:

I would start by visually thinking out this problem. Or if you have time sketch it out. And don't forget the popcorn :)

Then while doing this retry the problem

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3 years ago