Some one help pleaseeeeeeeeeee

Paha777 [63]

I think the answer is 23

8 0

3 years ago

Suppose you know the length of a confidence interval of a population mean is 8.4 and the sample mean (x bar) is 10. Find the ma

SOVA2 [1]

Answer:

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

The lenght of the interval correspond to:

$8.4 = 2ME$

$ME= \frac{8.4}{2}= 4.2$

And since we know the margin of error we can find the limits for the confidence interval:

$Lower = 10 -4.2=5.8$

$Upper = 10 +4.2=14.2$

Step-by-step explanation:

Previous concepts

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".

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".

$\bar X=10$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma$ represent the population standard deviation

n represent the sample size

Solution to the problem

Assuming the X follows a normal distribution

$X \sim N(\mu, \sigma)$

The sample mean $\bar X$ is distributed on this way:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

The confidence interval on this case is given by:

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

The margin of error is given by:

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

The lenght of the interval correspond to:

$8.4 = 2ME$

$ME= \frac{8.4}{2}= 4.2$

And since we know the margin of error we can find the limits for the confidence interval:

$Lower = 10 -4.2=5.8$

$Upper = 10 +4.2=14.2$

4 0

3 years ago

Smiths bakery is baking several large cakes for a community festival. The cakes consist of two geometrically similar shapes as s

Studentka2010 [4]

Answer:

Approximately 313 cakes of similar size as those 50 cut from the smaller cake, can be cut from the bigger cake.

Step-by-step explanation:

The complete question is with the missing image of the cakes is attached to this solution.

From the image provided, the dimensions of the smaller cake = 2 ft × 1.6 ft

The dimensions of the larger cake = 5 ft × 4 ft

50 cakes are obtained from the smaller cake, how many cakes can be obtained from the bigger cake?

Area of the smaller cake = 2 × 1.6 = 3.2 ft²

Area of the bigger cake = 5 × 4 = 20 ft²

3.2 ft² cake provides 50 cakes.

20 ft² cake will provide (20×50/3.2) cakes = 312.5 cakes

Rounded to the nearest piece of cake = 313 cakes

Hope this Helps!!!

6 0

3 years ago

Read 2 more answers

If Earths rotation on its axis takes 24 hours in in many minutes does it take to rotate in one week? (1 hour=60 minutes)

mixas84 [53]

Answer:

420

Step-by-step explanation:

im not sure i just multiply 60×7

4 0

3 years ago

What is the sum of all the positive three-digit numbers whose digits are all odd?\?

MakcuM [25]

The correct answer: Still an odd number.

Odd numbers added together are still odd numbers. It still works even if we add a million digit odd number and add it to 3. So, adding all 3-digit odd numbers together will still yield an odd number. Here is an example:

We will be adding 7 3-digit odd number samples from 100, 200, and 300. And then we will be adding the results just to see if it will become odd or even.

101 + 103 + 105 + 107 + 109 + 111 + 113 = 749 <--- Odd
201 + 203 + 205 + 207 + 209 + 211 + 213 = 1449 <--- Odd
301 + 303 + 305 + 307 + 309 + 311 + 313 = 2149 < --- Odd

Now, let us add the results.

749 + 1449 + 2149 = 4347 <--- Still odd

Based on our little experiment, the answer is still odd. In my opinion, for us to change the result of adding all 3-digit odd numbers to even, we must multiply the result to 2 or by adding the result by itself. Example A + A = 2A.

6 0

3 years ago