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3 years ago

Please help ASAP PL u will get 15 points and brainliest

Mathematics

1 answer:

inysia [295]3 years ago

6 0

To be a function each different x value would have a different Y value.

First one is a function, there are no repeated Y values.

The second one is a function.

Third one is not a function because it has two identical Y values with different x values.

The fourth one is a function.

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mr yosgi has 75 papers he graded 60 of them and let a student grade the rest what percent if the papers did each person grade?

Alika [10]

He graded 60/75 papers.

If you divide these numbers instead of trying to simplify it equals the decimal 0.8.

If you move the decimal point two places to the right it's 80%.

6 0

4 years ago

Lauren spent 24 hours on the computer last week. She spent 2/3 of the time doing homework. How much time did Lauren spend doing

-BARSIC- [3]

Answer:

If Lauren spend 2/3 of her 24-hour computer time doing homework, this means she spent 16 hours doing homework. Each third of the 24 hours is 8 hours, so two thirds would be 16 hours.

6 0

3 years ago

Read 2 more answers

Need in depth explanation please

zysi [14]

Answer:

Y = 18

X = 9

Step-by-step explanation:

all the steps are in the picture. comment if you have any doubts.

4 0

2 years ago

Crayola makes 3 red crayons for every 2 brown crayons. On Tuesday, their factory made 1,000 more red crayons than brown. How man

miskamm [114]

Answer:

They make 2000 brown crayons on that day.

Step-by-step explanation:

Given:

Crayola makes 3 red crayons for every 2 brown crayons.

On Tuesday, their factory made 1,000 more red crayons than brown.

Now, to find the number of brown crayons they make that day.

Let the numbers of brown crayons be $x.$

So, the number of red crayons = $1000+x.$

As given, 3 red crayons for every 2 brown crayons.

So, the ratio is 3:2.

Thus, 3 is equivalent to 2.

So, 1000+ $x$ is equivalent to $x.$

Now, to get the number of brown crayons by using cross multiplication method:

$\frac{3}{2} =\frac{1000+x}{x}$

By cross multiplying we get:

$3x=2000+2x$

Subtracting both sides by 2 $x$ we get:

$x=2000.$

Therefore, they make 2000 brown crayons on that day.

7 0

3 years ago

"The municipal transportation authority determined that 58% of all drivers were speeding along a busy street. In an attempt to r

vredina [299]

Answer:

a) X=77 drivers

b) Power of the test = 0.404

c) Increasing the sample size.

Step-by-step explanation:

This is a hypothesis test of proportions. As the claim is that the speed monitors were effective in reducing the speeding, this is a left-tail test.

For a left-tail test at a 5% significance level, we have a critical value of z that is zc=-1.645. This value is the limit of the rejection region. That means that if the test statistic z is smaller than zc=-1.645, the null hypothesis is rejected.

The proportion that would have a test statistic equal to this critical value can be expressed as:

$p_c=\pi+z_c\cdot\sigma_p$

The standard error of the proportion is:

$\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.58*0.42}{150}}\\\\\\ \sigma_p=\sqrt{0.001624}=0.04$

Then, the proportion is:

$p_c=\pi+z_c\cdot\sigma_p=0.58-1.645*0.04=0.58-0.0658=0.5142$

This proportion, with a sample size of n=150, correspond to

$x=n\cdot p=150\cdot0.5142=77.13\approx 77$

The power of the test is the probability of correctly rejecting the null hypothesis.

The true proportion is 0.52, but we don't know at the time of the test, so the critical value to make a decision about rejecting the null hypothesis is still zc=-1.645 corresponding to a critical proportion of 0.51.

Then, we can say that the probability of rejecting the null hypothesis is still the probability of getting a sample of size n=150 with a proportion of 0.51 or smaller, but within a population with a proportion of 0.52.

The standard error has to be re-calculated for the new true proportion:

$\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.52*0.48}{150}}\\\\\\ \sigma_p=\sqrt{0.001664}=0.041$

Then, we calculate the z-value for this proportion with the true proportion:

$z=\dfrac{p-\pi'}{\sigma_p}=\dfrac{0.51-0.52}{0.041}=\dfrac{-0.01}{0.041}=-0.244$

The probability of getting a sample of size n=150 with a proportion of 0.51 or lower is:

$P(p$

Then, the power of the test is β=0.404.

The only variable left to change in the test in order to increase the power of the test is the sample size, as the significance level can not be changed (it is related to the probability of a Type I error).

It the sample size is increased, the standard error of the proprotion decreases. As the standard error tends to zero, the critical proportion tend to 0.58, as we can see in its equation:

$\lim_{\sigma_p \to 0} p_c=\pi+ \lim_{\sigma_p \to 0}(z_c\cdot\sigma_p)=\pi=0.58$

Then, if the critical proportion increases, the z-score increases, and also the probability of rejecting the null hypothesis.

5 0

4 years ago