Stats Test 2

Question 1

What does the symbol m stand for?

Answer 1

margin of error

Question 2

As sample size increases, what happenes to m?

Answer 2

decreases

Question 3

As confidence increases, what happenes to m?

Answer 3

increases

Question 4

What does a hypothesis test or significance test do?

Answer 4

Tells us if there’s a real difference (not a significant difference.)

Question 5

if p <= a…

Answer 5

Reject Ho

Question 6

if p > a…

Answer 6

Fail to reject Ho due to insufficient evidence

Question 7

What is the related measure of certainty?

Answer 7

alpha or a

Question 8

What are the degrees of freedom?

Answer 8

sample size - 1 or n - 1

Question 9

What is the result of a confidence interval test

Answer 9

a confidence interval using a margin of error

Question 10

What is the result of a Hypothesis test

Answer 10

Reject or fail to reject

Question 11

For statistical inference, what conditions must be met?

Answer 11

Randomness and Normal population or Large sample (n>=30)

Question 12

Examples of natural variation

Answer 12

Raw material, human performance, equipment performance measurement

Question 13

Examples of unnatural variation

Answer 13

Bad batch, broken machine, poorly trained operator

Question 14

What are generally the bounds for a control chart?

Answer 14

+3sd and -3sd

Question 15

Under what conditions does a control chart fail

Answer 15

One point outside of the limits or nine points on one side in a row

Question 16

Estimator

Answer 16

A general statistic that estimates the parameter (x bar or s)

Question 17

Estimate

Answer 17

A specific value of an estimator

Question 18

Confidence interval wording

Answer 18

We are % confident that x lies between a and b

Question 19

What does NOT go into confidence interval wording

Answer 19

Probability (in terms of the confidence percentage) (It’s either right or it’s wrong)

Question 20

What is standard error

Answer 20

s/sqrt(n)

Question 21

What is margin of error

Answer 21

t * s/sqrt(n)

Question 22

What is the significance of alpha?

Answer 22

It is the chance of rejecting a correct null hypothesis

Question 23

What is the effect size?

Answer 23

x(bar) - mu

Question 24

Two sided test require…

Answer 24

More evidence than a one sided test

Question 25

Confidence tests and Hypothesis tests only agree if

Answer 25

If Ha is two sided and
Confidence % + a = 1

Question 26

What type of error is a Type I error?

Answer 26

H0 is true but gets rejected

Question 27

What type of error is a Type II error?

Answer 27

H0 is not true but fails to be rejected

Question 28

What is the representation of the chance of a Type I error?

Answer 28

alpha

Question 29

What is the representation of the chance of a Type II error?

Answer 29

beta

Question 30

What is power?

Answer 30

the inverse of beta (1 - beta), or the chance to reject a null hypothesis if it is false

Question 31

What is the relationship between alpha and beta?

Answer 31

Inverse

Question 32

What is the relationship between alpha and Power?

Answer 32

Direct