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3 years ago

Is it possible for a simple, connected graph that has n vertices all of different degrees? Explain why or why not.

Mathematics

1 answer:

ryzh [129]3 years ago

8 0

Answer:

It isn't possible.

Step-by-step explanation:

Let G be a graph with n vertices. There are n possible degrees: 0,1,...,n-1.

Observe that a graph can not contain a vertice with degree n-1 and a vertice with degree 0 because if one of the vertices has degree n-1 means that this vertice is adjacent to all others vertices, then the other vertices has at least degree 1.

Then there are n vertices and n-1 possible degrees. By the pigeon principle there are two vertices that have the same degree.

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A train traveling south leaves the station at a constant rate of 62 kilometers per hour. A second train traveling north leaves t

malfutka [58]

Answer: 3.5 hours

Step-by-step explanation:

68 + 62 = 130

455 / 130 = 3.5

Hope this helps you! :)

7 0

3 years ago

Read 2 more answers

How would you go about finding the area and perimeter of a composite figure?

fgiga [73]

Explanation:

The area is the sum of the areas of the non-overlapping parts. The figure is called "composite" because it is composed of figures whose area formulas you know. Decompose the figure into those, find the area of each, then sum those areas to find the area of the whole.

For example

If the figure consists of a rectangle and semicircle, find the areas of each of those. Then add the areas together to find the total area.

Likewise, the perimeter of a composite figure will be the sum of the "exposed" perimeters of the parts. (Some edges of the figures making up the composition will be internal, so do not count toward the perimeter of the composite figure.)

For example

If the curved edge of the semicircle of the figure described in the example above is part of the perimeter, then its length will be half the circumference of a circle. If the straight edge of the semicircle is "internal" and not a part of the perimeter, its length (the diameter of the semicircle) may need to be partially or wholly subtracted from the perimeter of the rectangle, depending on the actual arrangement of the composite figure. In other words, add up the lengths of the edges that "show."

_____

Additional comments

In the above, we have described how to add the areas of parts of the figure. In some cases, it can be easier to identify a larger figure, or one that is more "complete", then subtract the areas of the parts that aren't there. For example, an L-shaped figure can be decomposed into two rectangles. Or it can be decomposed into a larger rectangle covering the entire outside dimensions, from which a smaller rectangle is subtracted to leave the L-shape. Depending on how dimensions are shown, one computation or the other may be easier.

Likewise, for the purposes of computing the perimeter, lines of the figure may be rearranged in any convenient way, as long as their total length doesn't change. The L-shape just described will have a perimeter exactly equal to the perimeter of the rectangle that encloses its outside dimensions, for example. You can see this if you move the two lines forming the concave edges.

Familiarity with area formulas can help with area. For example, you know that the area of a triangle is the same as that of a rectangle half the height. Likewise, the area of a trapezoid is the area of a rectangle with the same height and a width equal to the midline of the trapezoid.

5 0

3 years ago

If you draw a net for a cylinder, such as a soup can, how many two-dimensional geometric shapes would this net have?

Nezavi [6.7K]

Answer:

If you were to “unroll” a can of soup, you would end up with two circles and one rectangle.

Thats why when you are finding the surface area of a cylinder, you need to multiply the area of the circle by 2. And also you need to find the area of the rectangle. Then you add the areas all up.

please mark me brainlies :)

I need 3 more to become an expert

6 0

3 years ago

Read 2 more answers

After once again losing a football game to the college'ss arch rival, the alumni association conducted a survey to see if alumni

antoniya [11.8K]

Answer:

a) The 90% confidence interval would be given (0.561;0.719).

b) $p_v =P(z>2.8)=1-P(z$

c) Using the significance level assumed $\alpha=0.01$ we see that $p_v$ so we have enough evidence at this significance level to reject the null hypothesis. And on this case makes sense the claim that the proportion is higher than 0.5 or 50%.

Step-by-step explanation:

1) Data given and notation

n=100 represent the random sample taken

X=64 represent were in favor of firing the coach

$\hat p=\frac{64}{100}=0.64$ estimated proportion for were in favor of firing the coach

$p_o=0.5$ is the value that we want to test since the problem says majority

$\alpha$ represent the significance level (no given, but is assumed)

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

p= population proportion of Americans for were in favor of firing the coach

Part a

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 90% confidence interval the value of $\alpha=1-0.9=0.1$ and $\alpha/2=0.05$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.64$

And replacing into the confidence interval formula we got:

$0.64 - 1.64 \sqrt{\frac{0.64(1-0.64)}{100}}=0.561$

$0.64 + 1.64 \sqrt{\frac{0.64(1-0.64)}{100}}=0.719$

And the 90% confidence interval would be given (0.561;0.719).

Part b

We need to conduct a hypothesis in order to test the claim that the proportion exceeds 50%(Majority). :

Null Hypothesis: $p \leq 0.5$

Alternative Hypothesis: $p >0.5$

We assume that the proportion follows a normal distribution.

This is a one tail upper test for the proportion of union membership.

The One-Sample Proportion Test is "used to assess whether a population proportion $\hat p$ is significantly (different,higher or less) from a hypothesized value $p_o$ ".

Check for the assumptions that he sample must satisfy in order to apply the test

a)The random sample needs to be representative: On this case the problem no mention about it but we can assume it.

b) The sample needs to be large enough

$np_o =100*0.64=64>10$

$n(1-p_o)=100*(1-0.64)=36>10$

Calculate the statistic

The statistic is calculated with the following formula:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o(1-p_o)}{n}}}$

On this case the value of $p_o=0.5$ is the value that we are testing and n = 100.

$z=\frac{0.64 -0.5}{\sqrt{\frac{0.5(1-0.5)}{100}}}=2.8$

The p value for the test would be:

$p_v =P(z>2.8)=1-P(z$

Part c

Using the significance level assumed $\alpha=0.01$ we see that $p_v$ so we have enough evidence at this significance level to reject the null hypothesis. And on this case makes sense the claim that the proportion is higher than 0.5 or 50%.

6 0

3 years ago

A sum of 450 Euros is invested at 3.2% per annum at compound interest. The following formula expresses the value of the investme

Anon25 [30]

Answer:

u have to eat mcdonalds

Step-by-step explanation:

7 0

3 years ago