Exam 2- sampling distributions

Question 0

Approximate sampling distribution of x- bar is

Answer 0

The distribution of x- bar values obtained from repeatedly taking SRSs of the same size from the same population

Question 1

Theoretical sampling distribution of x- bar is

Answer 1

The distribution of all x- bar values from all possible samples of the same size from the same population

Question 2

Center

The mean of the sampling distribution of x- bar …. the mu….

Answer 2

Equals ….. Population mean

Question 3

Mean =mu is valid for

Answer 3

All sample sizes and populations of all shapes

Question 4

Spread

The standard deviation of the sampling distribution of x- bar …..

Answer 4

Equals the standard deviation of the population divided by the square root of n

Valid for all sample sizes and population of all shapes

Question 5

Shape

For non-normal population

Answer 5

Shape of sampling distribution of x-bar is approximately normal when n is large

Question 6

Shape

For normal population

Answer 6

Shape of the sampling distribution if x- bar is exactly normal for any n

Question 7

Mean …… equals mu regardless of population shape or sample size

Answer 7

Exactly

Question 8

Standard deviation of x- bar is always ….. Than the standard deviation of the population for samples of any size where ….

Answer 8

Less. n>1

Question 9

Standard deviation of c- bar gets ….as n increases at rate ….

Answer 9

Smaller…. Square root of n

Question 10

To cut standard deviation in half

Answer 10

Quadruple sample size

Question 11

Shape is normal if population is …..for any sample size

Answer 11

Normal

Question 12

Shape is approximately normal if we take a …… ……. ……. from a non- normal population

Answer 12

Large random sample

Question 13

The population distribution of a variable is

Answer 13

The distribution of values of the variable among all the individuals in the population

Question 14

The sampling distribution of a statistic is

Answer 14

The distribution of values taken by the statistic in all possible samples of the same size from the same population

Question 15

The population distribution describes the ….. that make up the population

Answer 15

Individuals

Question 16

A sampling distribution describes how …. Varies in many samples from the population

Answer 16

Statistic

Question 17

What is distribution of random variable?

Answer 17

A list of all possible values of a variable together with how often each value occurs

Question 18

The probability of an event can be defined as

Answer 18

The fraction of time the event will occur if random phenomenon is related many time

Question 19

Central Limit Tgeorem

Answer 19

If you take a large SRS of size n from any population then the sampling distribution of x- bar is approximately not mail

Question 20

The central limit theorem on x- bar requires

Answer 20

A large random sample

Question 21

A correlation of r=0 indicates

Answer 21

That x and y are not linearly related

Question 22

T/F probabilities on individuals can only be computed using the standard Normal table if the population is Normally distributed

Answer 22

True

Question 23

What does the probability distribution of a random variable gives us?

Answer 23

All possible values if the random variable together with their probabilities

Question 24

T/F because there is a probability assigned to each event, the probability model is correct

Answer 24

T

Question 25

T/f because all probabilities are between zero and one, and because the sum of all probabilities is 1, the probability model is correct

Answer 25

True

Question 26

The law of the large numbers refers to the .... Of a ..... Not to the sampling distribution of x- bar

Answer 26

Mean of a sample

Question 27

What does the Law of Large numbers tell us?

Answer 27

As sample size increases, the variable x-bar from a random sample gets closer and closer to mu

Question 28

The mean x-bar of all possible samples will exactly equal to the population mean or would that a mean of a sampling distribution x-bar that would be equal mu?

Answer 28

The mean of the sampling distribution will equal mu