Chapter 5

Question 1

Sample Statistics

Answer 1

Summarizes sample characteristics

Question 2

Parameters

Answer 2

Summarize population characteristics

Question 3

Sample Mean

Answer 3

Mean of the sample,

Question 4

Sample Proportion

Answer 4

Proportion of sample,

Question 5

Population Mean

Answer 5

Mean of the population,

Question 6

Population Proportion

Answer 6

True proportion, p

Question 7

Statistic as a RV

Answer 7

Statistic is a random variable and will have a distribution assigning probabilities to different samples

Question 8

Sampling Distribution

Answer 8

Probability distribution of sample statistics, tells us how much a statistic would vary from sample to sample

Question 9

Mean of Sample Proportion

Answer 9

Mean p

Question 10

Standard Deviation of Sample Proportion

Answer 10

SD

Question 11

When is distribution approximately normal?

Answer 11

When for a sample size n with true proportion p, both np and n(1-p) are greater than or equal to 15

Question 12

Normal Distribution of Sample Proportion

Answer 12

Question 13

Standard Error

Answer 13

Estimate of standard deviation of sampling distribution

Question 14

What happens to standard deviation as sample size n increases?

Answer 14

Standard deviation decreases

Question 15

Smaller the standard deviation…

Answer 15

…closer the sample proportion is to the population proportion

Question 16

Empirical Rule

Answer 16

Nearly all sample proportions for size n with true proportion p will lie between

Question 17

Probability with Normal Distribution and pHat

Answer 17

Question 18

Sample mean distribution centered around…

Answer 18

True population mean mu

Question 19

Sample mean distribution standard deviation

Answer 19

Question 20

Sample Mean Normal Distribution

Answer 20

Question 21

What does increasing sample size n do to sample means?

Answer 21

Vary less and less tending toward true population mean

Question 22

Central Limit Theorem

Answer 22

As sample size increases, sampling distribution of sample mean tends to a normal distribution, even if population distribution far from bell-shaped

Question 23

Ensuring normal distribution for standard mean

Answer 23

n greater than or equal to 30

Question 24

Statistical Inference

Answer 24

Making decisions about parameters using statistics

Question 25

Point Estimation

Answer 25

Single estimate for population parameter, usually sample mean

Question 26

Interval Estimation

Answer 26

Form a confidence interval of population parameter within which true parameter value is believed to lie at a certain confidence level

Question 27

Significance Test

Answer 27

Yields decision on whether claim about value of parameter is supported by data observed from a random sample

Question 28

C + E Model

Answer 28

Center + Error ; usually C is the sample mean and E is the margin of error

Question 29

Confidence Level

Answer 29

Level of confidence with which method produces an interval that contains the true parameter value

Question 30

100% Confidence Level

Answer 30

Not relevant, would be all possible values

Question 31

Margin of Error

Answer 31

How accurately the statistic estimates unknown parameter

Question 32

General form of C + E Confidence Interval

Answer 32

Question 33

Robust

Answer 33

A procedure that performs adequately even when a particular assumption is violated

Question 34

Standard Error and T-Score as sample size increases (or, if CI decreases)

Answer 34

The two decrease and the margin of error likewise decreases, so the CI gets shorter

Question 35

How CI changes with fixed sample size if CI increases...

Answer 35

T-Score and margin of error increase so the CI gets wider

Question 36

How to think about CI

Answer 36

1. We are X% confident that the true population mean lies between the lower and upper bounds 2. Of 100 X% intervals calculated the same way, we expect X of them to contain the true population mean 3. In a long series of repeated trials, X% of the intervals will contain the true population mean