9n+21−3n−24 simplify

#13 I'm not sure how to do it ;~; I need help pls

DerKrebs [107]

You have climbed 3/4 of the wall and you are 24 feet above the ground. The best equation I can think 24/3 + 24 = h.

4 0

3 years ago

Rewrite the equation by completing the square.

Dennis_Churaev [7]

Once you complete the square, the simplified version of this equation is

(2x - 1)^2= 0

If you want to solve for x, subtract 1 and divide by 2.

x = 0.5

7 0

4 years ago

A soccer ball manufacturer wants to estimate the mean circumference of soccer balls within 0.1 in. Determine the minimum sample

leva [86]

Answer:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (2)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025,0,1)", and we got $z_{\alpha/2}=1.96$ , replacing into formula (2) we got:

$n=(\frac{1.96(0.25)}{0.1})^2 =24.01$

So the answer for this case would be n=25 rounded up to the nearest integer

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=0.25$ represent the population standard deviation

n represent the sample size (variable of interest)

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

And on this case we have that ME =0.1 and we are interested in order to find the value of n, if we solve n from equation (1) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (2)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025,0,1)", and we got $z_{\alpha/2}=1.96$ , replacing into formula (2) we got:

$n=(\frac{1.96(0.25)}{0.1})^2 =24.01$

So the answer for this case would be n=25 rounded up to the nearest integer

8 0

4 years ago

math club has 36 members of which 13 are males and the rest are females. what is the ratio of females to males.

FinnZ [79.3K]

You would have to subtract 13 from 36 to find the amount of females.

36-13 = 23

there must be 23 females

23:13 is the ratio

7 0

3 years ago

What did the Japanese adapt from Chinese

Shalnov [3]

I think the answer is Hinduism

8 0

3 years ago