Write a description of the set. {April,August}

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard devia

Arturiano [62]

Answer:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 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)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

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

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

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

The margin of error is given by this formula:

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

And on this case we have that ME =+5 and we are interested in order to find the value of n, if we solve n from equation (2) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 rounded up to the nearest integer

4 0

3 years ago

Can some help me fast!

Mice21 [21]

Answer:

5x +2y =38

5(6) +2y = 38

30 +2y= 38

2y= 8

y= 4

(6, 4)

5(0) +2y =38

2y= 38

y= 19

(0,19)

5(-2) +2y= 38

-10 +2y =38

2y= 48

y=24

(-2,24)

7 0

2 years ago

CAN ANYONE HELP ME ANSWER THIS PLEASE

HACTEHA [7]

Answer: 14/45

Step-by-step explanation: The probability that they first event will occur is 2/10. The probability that the second event will occur is 1/9. If you multiply those like it says in the hint you will get 14/45. (I think this is right)

5 0

3 years ago

Solve psl brainliest

DIA [1.3K]

Answer:

Mixed number: 8 and 4/100

Improper fraction: 804/100

Since it says to not simplify, those are the answers.

7 0

2 years ago

Read 2 more answers

Imagine you have a classmate who has never had an introduction to statistics in a math course. Explain to that person how the pr

Tamiku [17]

Answer:

Probability of selecting red tile out of a box containing 3 red,2 white & 5 black tiles = 3/10 = 0.3

Step-by-step explanation:

Probability is the calculation of likelihood of an event.

It can be calculated by Formula : Favourable outcome / Total Outcomes

Example : If a box contain 3 red tiles, 2 white tiles, 5 black tiles

Prob (selecting a red tile) = Favourable outcome (red tiles) / Total Outcomes (total tiles) = 3 / 10 = 0.3

Similarly, prob (white tile) & prob (black tile) = 2/10 ie 0.2 & 5/10 ie 0.5 respectively

8 0

3 years ago