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Alex
3 years ago
13

Could someone explain this to me ??

Mathematics
1 answer:
hodyreva [135]3 years ago
3 0
<h3>Answer: C) 12</h3>

========================================================

Explanation:

Refer to the diagram below. I'm using the points A,B,C,D,E to help label the triangles, and to label the angles as well.

For now, let's focus on triangle DEC.

The top most angle is given as D = 65. Note how the angles D and E are opposite the congruent lines (marked with the red single tickmarks). This means that angles D and E are congruent to one another. So E = 65 as well. This is shown in the diagram below.

For now we don't know what angle C is, so we'll call it y. More specifically, we'll make y the measure of angle DCE.

For any triangle, the three angles always add to 180

y+65+65 = 180

y+130 = 180

y = 180-130

y = 50

So angle DCE is 50 degrees.

-------------------------------

Now we move onto triangle ABC.

Because angles DCE and ACB are vertical angles, this makes angle ACB 50 degrees also. Effectively, anywhere you see a 'y' in the diagram below, replace it with 50.

So triangle ABC has the three angles y = 50, y = 50 and 7x-4

We can solve for x like so

y+y+(7x-4) = 180

50+50+(7x-4) = 180

7x+96 = 180

7x = 180-96

7x = 84

x = 84/7

x = 12

This points to choice C as the final answer.

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Select the correct answer.
tigry1 [53]

Answer:

We can be 95% certain that the sample mean will fall within $44.87 and $46.93

Step-by-step explanation:

Empirical Rule:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

Central Limit Theorem:

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean \mu and standard deviation \sigma, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean \mu and standard deviation s = \frac{\sigma}{\sqrt{n}}.

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Population:

Mean $45.90, standard deviation $10.31.

Sample:

By the Central limit theorem, mean $45.90, standard deviation s = \frac{10.31}{\sqrt{400}} = \frac{10.31}{20} = 0.5155

Which interval can the branch manager be 95% certain that the sample mean will fall within?

By the Empirical Rule, within 2 standard deviations of the mean. So

45.90 - 2*0.5155 = $44.87

45.90 + 2*0.5155 = $46.93

We can be 95% certain that the sample mean will fall within $44.87 and $46.93

6 0
2 years ago
Read 2 more answers
A volleyball player serves the ball from a height of 6.5 feet above the ground with an initial vertical velocity of 21 feet per
Vaselesa [24]

Answer:

Option D. H(t) = 6.5+21t-16t^2

Step-by-step explanation:

we know that

If air resistance is ignored, the height h (in feet) of the ball t seconds after it is served is given by

H(t) = - \frac{1}{2}g t^2 + V_0t + H_0

where

g is the acceleration due to gravity which on earth is approximately equal to 32 feet / sec^2

V_0 is the initial velocity (when t = 0 )

H_0 is the initial height (when t = 0)

In this problem we have

V_0=21\ ft/sec\\H_0=6.5\ ft

substitute the given values

H(t) = - \frac{1}{2}(32) t^2 + (21)t + 6.5

H(t) = -16t^2 + 21t + 6.5

Rewrite

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3 years ago
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Alla [95]
You'll need to add 2 3/7 to <span> 3 4/7 to make 6. 
3 + 2 = 5 4/7 + 3/7 = 7/7 =1 
5+1=6</span>
6 0
3 years ago
Which sign makes this number sentence true? |78| __ |-222|
sineoko [7]
The absolute value of 78 is < the absolute value of -222
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Alex17521 [72]

Answer: 14.353 or 18.647

Step-by-step explanation:

Hi.

Subtracting:

16.5 - 2.147 = 14.353

Adding:

16.5 + 2.147 = 18.647

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