All categories

2 years ago

Question 3 of 21

Mathematics

1 answer:

ankoles [38]2 years ago

5 0

Answer: C

Step-by-step explanation:

The inverse of a function maps the domain onto the range.

You might be interested in

5^2+x^2=10^2<br><br> What Is X and how do you find the angles for it?

Anvisha [2.4K]

If you work out the constants it says:

25+x²=100

Which simplifies to x=√75 or x=-√75

4 0

3 years ago

The water works commission needs to know the mean household usage of water by the residents of a small town in gallons per day.

valina [46]

Answer:

A sample of 179 is needed.

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:

$\alpha = \frac{1 - 0.85}{2} = 0.075$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.075 = 0.925$ , so Z = 1.44.

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.

A previous study found that for an average family the variance is 1.69 gallon?

This means that $\sigma = \sqrt{1.69} = 1.3$

If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?

A sample of n is needed, and n is found for M = 0.14. So

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

$0.14 = 1.44\frac{1.3}{\sqrt{n}}$

$0.14\sqrt{n} = 1.44*1.3$

$\sqrt{n} = \frac{1.44*1.3}{0.14}$

$(\sqrt{n})^2 = (\frac{1.44*1.3}{0.14})^2$

$n = 178.8$

Rounding up

A sample of 179 is needed.

7 0

3 years ago

A girl scout troop sold cookies. If the girls sold 5 more boxes the second week than they did the first, and if they double the

valina [46]

Answer:

Boxes sold first week = 104

Boxes sold second week =x+5= 104+5=109

Boxes sold third week = 109 times 2= 218

Step-by-step explanation:

Let x be the number of boxes sold in first week

the girls sold 5 more boxes the second week

So number of boxes sold in second week is x+5

they double the sales of the second week for the third week

So number of boxes sold in third week is 2 (x+5)

Total boxes sold is 431

$x+x+5+2(x+5)=431$

$x+x+5+2x+10=431$

$4x+15=431$

subtract 15 from both sides

$4x=416$

divide by 4 on both sides

$x=104$

Boxes sold first week = 104

Boxes sold second week =x+5= 104+5=109

Boxes sold third week = 104 times 2= 218

4 0

3 years ago

Solving quadratic equation using the completing method.<br>(a).x^2+6x+1=0

irina1246 [14]

Answer:

$x = -3 + 2\sqrt2 \ , \ x = -3 - 2\sqrt2$

Step-by-step explanation:

x² + 6x + 1 = 0

a = 1 , b = 6 , c = 1

$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\\\\x = \frac{-6 \pm \sqrt{36-4}}{2}\\\\x=\frac{-6 \pm \sqrt{32}}{2}\\\\x= \frac{-6 \pm \sqrt{16 \times 2}}{2}\\\\x = \frac{-6 +4\sqrt2 }{2}\\\\x = -3 + 2\sqrt2 \ , \ x = -3 - 2\sqrt2$

7 0

3 years ago

Read 2 more answers

Evaluate y5 + x(-7)<br> When x = 2, y = -5

Ymorist [56]

Answer:

Step-by-step explanation:

OK, first we turn the variables into into the actual values:

The equation will look like this:

(2)5 + (-5)(-7)

Now its easier to solve! Lets solve (2)5!

2 * 5 = 10

The equation looks like:

10 + (-5)(-7)

We will also solve (-5)(-7). Remember that a negative number times a negative number is positive!

-5 * -7 = 35

Lets finish the rest:

10 + 35 = 45.

Hope this is correct and have a nice day!

3 0

3 years ago