Chapters 7 and 8 Test 3 Review Flashcards Preview

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Flashcards in Chapters 7 and 8 Test 3 Review Deck (17)
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1

If alpha is known, what are the assumptions that come with it?

That it is a simple random mean.
It is a normal population or a large sample size.

2

What is a sample error?

It is the error that can occur from using a sample to estimate a population's characteristics.

3

What does the term "bar x" signify?

Sample mean

4

What does "sample distribution of a sample mean" mean?

It is the distribution of all possible sample means of sample size (bar x).

5

What does the xi stand for in the equation for the population standard deviation?

each of the numbers in the sample size

6

What does the "u" represent in the equation for the population standard deviation?

the mean of the population

7

What does the "N" stand for in the equation for the population standard deviation?

the size of the population

8

How do we find the standard deviation of the means of little samples of a population?

by using the formula for standard deviation

9

What is the central limit theorem?

For a relatively large sample size, the variable bar x is approximately normally distributed, regardless of the distribution of the variable under consideration.Increased sample sized makes this even better.

10

What is considered a large sample space?

30

11

How do you find the standard deviation of bar x?

standard deviation (of bar x)= standard deviation/ square root of n

12

What is the formula for finding the sampling distribution of a sample mean?

For the mean: (ux=u) the mean of the population is equal to the mean of the sample size
For the standard deviation: sigma (x)= sigma/ square root of n

13

Approximately 68% of all possible samples have means that lie within what of the population u?

sigma over square root of n

14

Approximately 95% of all possible samples have means that lie within what of the population u?

2 sigmas over the square root of n

15

Approximately 99/7% of all possible samples have means that lie within what of the population u?

3 sigmas over the square root of n

16

Approximately 100% percent of all possible samples have means within what of the population mean.

z alpha over 2

17

If a question asks "find the probability of bar x is it assumes a value between 2 different numbers" what formula do you use?

the z score one