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2 years ago

Please help I just can’t find the answer

Mathematics

2 answers:

Talja [164]2 years ago

4 0

Answer:

Step-by-step explanation:

Mumz [18]2 years ago

4 0

Answer:

The arc-length of the semicircle is approximately 34.54 units

Step-by-step explanation:

Recall that the arc length of the whole circumference is defined by the formula:

$Circumference's \,\,length=2\,\pi\,R$

where R is the radius of the circle (in your case 11 units)

So the length of half a circumference (which is actually the arc length of the semicircle you are requested to find) would be half of the formula we just mentioned:

$Arc\,\,length=\pi\,R\\Arc\,\,length= 3.14\,(11)\\Arc\,\,length= 34.54\, \,units$

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A museum conducts a survey of its visitors in order to assess the popularity of a device which

Natali5045456 [20]

Answer:

The appropriate null hypothesis is $H_0: p \geq 0.2$

The appropriate alternative hypothesis is $H_1: p < 0.2$

The p-value of the test is 0.1057 > 0.05, which means that there is not sufficient evidence that fewer than 20% of the museum visitors make use of the device, and so, it should not be withdrawn.

ii:

The p-value of the test is 0.1057

Step-by-step explanation:

Question i:

The device will be withdrawn if fewer than 20% of all of the museum’s visitors make use of it.

At the null hypothesis, we test if the proportion is of at least 20%, that is:

$H_0: p \geq 0.2$

At the alternative hypothesis, we test if the proportion is less than 20%, that is:

$H_1: p < 0.2$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

0.2 is tested at the null hypothesis:

This means that $\mu = 0.2, \sigma = \sqrt{0.2*0.8} = \sqrt{0.16} = 0.4$ .

The device will be withdrawn if fewer than 20% of all of the museum’s visitors make use of it. Of a random sample of 100 visitors, 15 chose to use the device.

This means that $n = 100, X = \frac{15}{100} = 0.15$

Test statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.15 - 0.20}{\frac{0.4}{\sqrt{100}}}$

$z = -1.25$

P-value of the test and decision:

The p-value of the test is the probability of finding a sample proportion below 0.15, which is the p-value of z = -1.25.

Looking at the z-table, z = -1.25 has a p-value of 0.1057.

The p-value of the test is 0.1057 > 0.05, which means that there is not sufficient evidence that fewer than 20% of the museum visitors make use of the device, and so, it should not be withdrawn.

Question ii:

The p-value of the test is 0.1057

7 0

3 years ago

In a new movie

Lady_Fox [76]

Answer. 655.4

Step-by-step explanation:

what did u get?

5 0

3 years ago

Julian walked 6/10 of a mile to his friends house and another 35/100 mile to the store. He walked 1/4 of a mile back home. Julia

AveGali [126]

The statement, "Julian's sister said he walked 1/5 mile" cannot be agreed because Julian totally walked $1\frac{1}{5} \text{ or } \frac{6}{5}$ miles.

Solution:

Given that,

Julian walked 6/10 of a mile to his friends house
Another 35/100 mile to the store
He walked 1/4 of a mile back home

To find total distance walked by Julian we have to add the above stated values. That is, $\frac{6}{10} +\frac{35}{100} +\frac{1}{4}$

Factors of 10 = $5\times2$

Factors of 100 = $5\times2\times5\times2$

Factors of 4 = $2\times2$

Therefore, the least common factor of 10, 100 and 4 is 100. With like denominators we can operate on just the numerators,

$\frac{6\times10}{10\times10} +\frac{35\times1}{100\times1} +\frac{1\times25}{4\times1}\rightarrow\frac{60+35+25}{100}\rightarrow\frac{120}{100}$

$\Rightarrow\frac{120}{100}\rightarrow\frac{6}{5}$

Which can also be written as $1\frac{1}{5}$ .

So, from the above calculation it can be said that Julian walked $1\frac{1}{5} \text{ miles }$ .

3 0

3 years ago

How do you find the height of a triangle (to calculate area)?

Lilit [14]

Answer:

The height of the triangle could be found by the Pythagoras theorem, where the result is, with the data of the exercise:

Height of the triangle = 10.392

And the area of the triangle is:

Area of the triangle = 31.176 units^2

Step-by-step explanation:

When you have two measurements of a triangle, as the case in the picture, you can find the third with the Pythagoras theorem, which is:

(opposite leg)^2 + (adjacent leg)^2 = hypotenuse^2

As you can see in the picture, the measurement of the hypotenuse is 12, and the opposite leg could be 6, for this reason, we're gonna clear the adjacent leg of the formula above:

(opposite leg)^2 + (adjacent leg)^2 = hypotenuse^2
(adjacent leg)^2 = hypotenuse^2 - (opposite leg)^2

Now, we can replace the values in the formula obtained:

(adjacent leg)^2 = hypotenuse^2 - (opposite leg)^2
(adjacent leg)^2 = 12^2 - 6^2
(adjacent leg)^2 = 144 - 36
(adjacent leg)^2 = 108

Now, as we just need the adjacent leg, we take the square root of both sides:

adjacent leg = $\sqrt{108}$
adjacent leg = 10.392 approximately.

Now, with these data, we can find the area of the triangle with the next formula:

Area of a triangle = (base * height) / 2
And we replace the measurements:
Area of a triangle = (6 * 10.392) / 2
Area of a triangle = 31.176

As the image does not contain units, it would be simply this number, however, you should know that the area units are usually given squared, for example: in^2 or ft^2.

4 0

2 years ago

Fill in the blank to make the expression a perfect square.. . u^2-16u+?

hram777 [196]

U² - 16 u + 64 = ( u - 8 )²
because: A² - 2 A B + B² = ( A - B )²
Answer: 64

8 0

3 years ago