Which formula can be used to find the nth term of a geometric sequence where the fifth term isn1/16 and the common ratio is 1/4?

In a random sample of 80 teenagers, the average number of texts handled in a day is 50. The 96% confidence interval for the mean

Nastasia [14]

Answer:

a) $\bar X =\frac{46+54}{2}=50$

And the margin of error is given by:

$ME= \frac{54-46}{2}= 4$

The confidence level is 0.96 and the significance level is $\alpha=1-0.96=0.04$ and the value of $\alpha/2 =0.02$ and the margin of error is given by:

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

We can calculate the critical value and we got:

$z_{\alpha/2} = 2.05$

And if we solve for the deviation like this:

$\sigma = ME * \frac{\sqrt{n}}{z_{\alpha/2}}$

And replacing we got:

$\sigma =4 *\frac{\sqrt{80}}{2.05} =17.45$

b) $ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}=2.05 *\frac{17.45}{\sqrt{160}}=2.828$

And as we can see that the margin of error would be lower than the original value of 4, the margin of error would be reduced by a factor $\sqrt{2}$

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

$\mu$ population mean (variable of interest)

$\sigma$ represent the population standard deviation

n=80 represent the sample size

Solution to the problem

Part a

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

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

For this case we can calculate the mean like this:

$\bar X =\frac{46+54}{2}=50$

And the margin of error is given by:

$ME= \frac{54-46}{2}= 4$

The confidence level is 0.96 and the significance level is $\alpha=1-0.96=0.04$ and the value of $\alpha/2 =0.02$ and the margin of error is given by:

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

We can calculate the critical value and we got:

$z_{\alpha/2} = 2.05$

And if we solve for the deviation like this:

$\sigma = ME * \frac{\sqrt{n}}{z_{\alpha/2}}$

And replacing we got:

$\sigma =4 *\frac{\sqrt{80}}{2.05} =17.45$

Part b

For this case is the sample size is doubled the margin of error would be:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}=2.05 *\frac{17.45}{\sqrt{160}}=2.828$

And as we can see that the margin of error would be lower than the original value of 4, the margin of error would be reduced by a factor $\sqrt{2}$

5 0

3 years ago

Jill measures some scrap boards in her garage to

Alika [10]

Answer: Yes, Jill has enough scrap boards to create a border around her garden.

Step-by-step explanation:

2.75 + 3.2 + 1.65 + 2.6 = 10.2 m

7 0

3 years ago

Read 2 more answers

What is the volume of a rectangular prism with a length of 7m, a hight of 9m and a width of 11m

vazorg [7]

Hello!

To find the Volume of the Rectangular Prism, you'll need to multiply all of the measurements together. So you'll need to multiply 7, 9, and 11 together.

V=7*9*11

First, you'll need to multiply 7 and 9. Once you've multiplied 9 and 7 together, you should have 63. Now you should multiply 63 and 11 together. Once you've multiplied 63 and 11 together, you should have a Volume of 693

You should have a Volume of 693m³

I hope this helps!

5 0

3 years ago

F(x) = 2x, find the ordered pair when x = 1. O (1,2) 0 (4,1) (2,1) O (1,4)

kenny6666 [7]

Answer:

The ordered pair is (1, 2) ⇒ A

Step-by-step explanation:

In the function f(x) = y

x is the domain of the function

y is the range of the function

The domain is all the x-coordinates of the points lie on the graph of the function

The range is all the y-coordinates of the points lie on the graph of the function

That means any ordered pair (x, y) satisfy the function f(x) = y, lies on the graph of the function

∵ f(x) = 2x

→ That means y = 2x

∵ x = 1

→ Substitute the value of x in the function above

∴ f(1) = 2(1)

∴ f(1) = 2

→ That means at x = 1, y = 2

∴ The ordered pair is (1, 2)

6 0

3 years ago

I need this answer asap! Thanks, See attached image bellow. <br> 40+ points!

Wewaii [24]

Answer:

rectangle

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers