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2 years ago

drew bought a chemistry book for $30. later that book was marked down by 20%. what was the cost of the book with the discount?

Mathematics

1 answer:

drek231 [11]2 years ago

3 0

Answer:

It would be 6 dollars

Step-by-step explanation:

20 percent of 30 dollars is 6 dollars.

If an item costs 30 dollars and it's on sale for 20 percent off, how much will you save? To figure this out, you need to find 20 percent of 30.

This is easy to do in your head. Think of what 10 percent would be. 10 percent of 30 would be the same as .10 x 30, or 3. So, 10 percent off is 3 dollars off.

20 percent is twice as much as 10 percent. If 10 percent off is 3 dollars, then 20 percent off would be 2 x 3 or 6.

20 percent of 30 dollars would be 6 dollars.

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An airline's public relations department claims that when luggage is lost, 88% is recovered and delivered to its owner within 24

melisa1 [442]

Answer:

The hypothesis statements are: H0: p = 0.88 versus HA : p < 0.88

The p-value of the test is 0.2483 > 0.1, which means that the data does not provide sufficient evidence to conclude that the proportion of times that luggage is returned within 24 hours is less than 0.88.

Step-by-step explanation:

Test if the proportion of times that luggage is returned within 24 hours is less than 0. 88

At the null hypothesis, we test if the proportion is of 0.88, that is:

$H_0: p = 0.88$

At the alternate hypothesis, we test if this proportion is less than 0.88, that is:

$H_a: p < 0.88$

The hypothesis statements are: H0: p = 0.88 versus HA : p < 0.88

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.

0.88 is tested at the null hypothesis:

This means that $\mu = 0.88, \sigma = \sqrt{0.88*0.12}$

A consumer group who surveyed a large number of air travelers found that 138 out of 160 people who lost luggage on that airline were reunited with the missing items by the next day.

This means that $n = 160, X = \frac{138}{160} = 0.8625$

Test statistic:

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

$z = \frac{0.8625 - 0.88}{\frac{\sqrt{0.88*0.12}}{\sqrt{160}}}$

$z = -0.68$

P-value of the test:

The p-value of the test is the probability of finding a sample proportion below 0.8625, which is the p-value of z = -0.68.

Looking at the z-table, the p-value of z = -0.68 is of 0.2483.

7 0

2 years ago

How do you solve this ???

galina1969 [7]

First you have to figure out how much a video game costs and how much a used one costs
Then you plug in the costs of the video games into Janets equation 120=3x+y
(x= video games and y=used video games)
Then you subtract the cost of video games from 120 and then divide that answer by the cost of used video games and that should give you how many used video games she can get

3 0

3 years ago

THE QUESTION IS DOWN BELOW.<br>major points when given branliest

emmainna [20.7K]

The ratios are Surface area ⇒ 4 : 25 Height ⇒ 2 : 5 and Volume ⇒ 8 : 125

<h3>How to determine the ratios?</h3>

The scale factor is given as:

m : n = 2 : 5

For the area, we take the square of the ratios.

i.e.

Area = 2^2 : 5^2

Evaluate

Area = 4 : 25

For the volume, we take the cube of the ratios.

i.e.

Volume = 2^3 : 5^3

Evaluate

Volume = 8 : 125

The given scale factor can be used for the height of the model and the original bicycle

Hence, the ratios are

Surface area ⇒ 4 : 25

Height ⇒ 2 : 5

Volume ⇒ 8 : 125