Solve: 3(2x - 5) = 6x

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

Which function is represented by the input-output table below? ( please help and thank you)

horsena [70]

the answer is A

if you multiply x by 3 then add 2 you get f(x)

8 0

4 years ago

Need help plz show your work how you did it

Arada [10]

8982/28

About 320 per classroom

6 0

4 years ago

4X+8<28<br> ayudenme por favor

VMariaS [17]

Answer:

x < 5.

Step-by-step explanation:

Creo que esto es correcto. :')

7 0

2 years ago

Heart failure is due to either natural occurrences (89%) or outside factors (11%). Outside factors are related to induced substa

Firdavs [7]

Answer:

a) 11% probability that the first patient with heart failure that enters the emergency room has the conditions due to outside factors.

b) 0.0871 = 8.71% probability that third patient with heart failure that enters the emergency room is the first one due to outside factors.

c) The mean number of heart failure patients with the condition due to natural causes that enter the emergency room before the first patient with heart failure from outside factors is 9.09.

Step-by-step explanation:

We have these following probabilities:

89% probability that a patient has heart failure due to natural occurrences.

11% probability that a patient has heart failure due to outside factors.

A) What is the probability that the first patient with heart failure that enters the emergency room has the conditions due to outside factors?

We assume that causes of heart failure between individuals are independent, which means that the probabilities are the same for each patient. So:

11% probability that the first patient with heart failure that enters the emergency room has the conditions due to outside factors.

B) What is the probability that third patient with heart failure that enters the emergency room is the first one due to outside factors?

First two due to natural occurrences, each with 89% = 0.89 probability.

Third due to outside factors, with 11% = 0.11 probability. So

0.89*0.89*0.11 = 0.0871

0.0871 = 8.71% probability that third patient with heart failure that enters the emergency room is the first one due to outside factors.

C) What is the mean number of heart failure patients with the condition due to natural causes that enter the emergency room before the first patient with heart failure from outside factors?

11% with outside factors, so the mean number of patients before the first with outside factors is given by

m = 1/0.11 = 9.09

The mean number of heart failure patients with the condition due to natural causes that enter the emergency room before the first patient with heart failure from outside factors is 9.09.

4 0

3 years ago

Solve: 3(2x - 5) = 6x - 15