11. What is 25? a. 10 b. 15 c. 32 d. 16

Mathematics

1 answer:

ikadub [295]3 years ago

8 0

Answer:

for what source

Step-by-step explanation:

You might be interested in

At a store, customers are randomly selected to participate in a survey. On Friday, there were 500 customers at the store. Out of

Svetlanka [38]

Divide the number of people selected by the total number of people.

90/500 = .18

This means that 18% of the customers were selected for the survey.

If the probability is the same on Saturday, then we can multiply the expected customers by our .18

700 x .18 = 126

126 should be selected for the survey on Saturday.

7 0

3 years ago

How many weeks of data must be randomly sampled to estimate the mean weekly sales of a new line of athletic footwear? We want 98

Irina18 [472]

Answer:

$n=(\frac{2.33(1400)}{400})^2 =66.50 \approx 67$

So the answer for this case would be n=67 rounded up

Step-by-step explanation:

Information given

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

$\mu$ population mean

$\sigma=1400$ represent the sample standard deviation

n represent the sample size

Solution to the problem

The margin of error is given by this formula:

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

And on this case we have that ME =400 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

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

The critical value for 98% of confidence interval now can be founded using the normal distribution. And the critical value would be $z_{\alpha/2}=2.33$ , replacing into formula (b) we got: