Find the value of x and m

A sample of 25 commuters in the Washington, D.C., area yielded the sample mean commute time of 27.97 minutes and sample standard

xxMikexx [17]

Answer:

The 99% confidence interval for the mean commute time of all commuters in Washington D.C. area is between 22.7994 minutes and 33.1406 minutes. The interpretation is that we are 99% sure that the true mean ommute time of all commuters in Washington D.C. area is between 22.7994 minutes and 33.1406 minutes.

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 Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.005 = 0.995$ , so $z = 2.575$

Now, find 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.

$M = 2.575*\frac{10.04}{\sqrt{25}} = 5.1706$

The lower end of the interval is the mean subtracted by M. So it is 27.97 - 5.1706 = 22.7994 minutes

The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 33.1406 minutes.

The 99% confidence interval for the mean commute time of all commuters in Washington D.C. area is between 22.7994 minutes and 33.1406 minutes. The interpretation is that we are 99% sure that the true mean ommute time of all commuters in Washington D.C. area is between 22.7994 minutes and 33.1406 minutes.

5 0

4 years ago

To make each costume, anushka used 3/4 yard of material. in all, she used 6 yards of material. how many costumes did anushka mak

lana [24]

She made 8 costumes. I can explain the math of you want. Just comment if you want me to do an explanation. Good luck.

5 0

3 years ago

Find the product of largest 4 digit number and smallest 3 digit number.

Afina-wow [57]

Largest 4 digit number =9999
Smallest 3 digit number= 100
So the product of 9999 x 100 = 999,900

3 0

3 years ago