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3 years ago

The value of y directly varies with the value of x. If y equals 21when x is 14, what is the value of y when x = 20?

Mathematics

1 answer:

Karo-lina-s [1.5K]3 years ago

8 0

Answer:

21×20÷14

=3×20÷2

=3×10

x=30

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John and Loretta Smith are in the 28% tax bracket. Their joint taxable income is $134,899. If the first $16,050 is taxed at 10%,

alexgriva [62]

0.10×16,050+0.28×(134,899−16,050) =34,882.72

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3 years ago

Read 2 more answers

you want to create a 99 confidence interval with a margin of error of 25 assuming that the population standard deviation is equa

Ahat [919]

Answer:

The minimum sample size is 239.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.99}{2} = 0.005$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.005 = 0.995$ , so Z = 2.575.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

Population standard deviation is equal to 1.5

This means that $\sigma = 1.5$

Margin of error of 0.25

This means that $M = 0.25$

What's the minimum size of the sample?

$M = z\frac{\sigma}{\sqrt{n}}$

$0.25 = 2.575\frac{1.5}{\sqrt{n}}$

$0.25\sqrt{n} = 2.575*1.5$

$\sqrt{n} = \frac{2.575*1.5}{0.25}$

$(\sqrt{n})^2 = (\frac{2.575*1.5}{0.25})^2$

$n = 238.7$

Rounding up:

The minimum sample size is 239.

4 0

3 years ago

Part A: Consider the equation x + 7 = 16. Which number from the set {5, 7, 9, 11} makes the equation true?

wel

Part A: Substitute/plug in each number into the equation to see which number will make the equation true.

x + 7 = 16 Plug in 5 into "x"

5 + 7 = 16

12 = 16 5 doesn't make the equation true because it equals 12 not 16

x + 7 = 16 Plug in 7 into "x"

7 + 7 = 16

14 = 16 7 doesn't make the equation true because it equals 14 not 16

x + 7 = 16 Plug in 9 into "x"

9 + 7 = 16

16 = 16 9 makes the equation true because it equals 16

Part B: Plug in 9 into "x" in the inequality to see if it still makes it true.

x + 7 < 16 [x plus 7 is less than 16]

9 + 7 < 16

16 < 16 [16 is less than 16] The same number would not make the inequality true because 16 can't be less than itself.

To figure out which numbers satisfy the inequality, plug it into the inequality:

x + 7 < 16 Plug in 5 into "x"

5 + 7 < 16

12 < 16 5 does satisfy the inequality because 12 is less than 16

x + 7 < 16 Plug in 7 into "x"

14 < 16 7 does satisfy the inequality because 14 is less than 16

x + 7 < 16 Plug in 11 into "x"

11 + 7 < 16

18 < 16 11 doesn't satisfy the inequality because 18 isn't less than 16

3 0

3 years ago

Don’t mind my handwriting but can someone help me please

Leno4ka [110]

Answer: A: 3/5

Step-by-step explanation:

He made 9 shots

He attempted 15

The ratio will be 9/15, which can be simplified to 3/5

Have a nice day :)

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2 years ago

Please help me on the math question!!!!!

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