Chapter 7

Question 0

p̂ (point estimate)

Answer 0

Sample proportion; unbiased; targets pop prop p̂=(upperCI+lower CI)/2

Question 1

p

Answer 1

Population proportion

Question 2

Point Estimate

Answer 2

A single value used to estimate the population perameter

Question 3

α

Answer 3

Complement of CI (CI+α=1)

Question 4

Confidence Interval (CI) (Interval Estimate)

Answer 4

Range of values used to estimate the true population parameter.

Question 5

Margin of Error (E) p̂ definition

Answer 5

The maximum likely difference between p̂ and p

Question 6

Critical Value

Answer 6

z score separating sample stats that are likely and unlikely to occur (Zα/2 in normal dist.)

Question 7

Margin of Error (E) p̂ equation

Answer 7

E=zα/2✓p̂q̂/n, n=#sample values.

p̂-E<p><p̂+E, E=(upperCI-lower CI)/2

Question 8

CI for p̂ requirements

Answer 8

1. Simple random samples 2. fixed # trials 3. independent trials 4. 2 outcomes 5. P of S is constant

Question 9

Confidence Level (degree of confidence) (confidence coefficient)

Answer 9

Probability of success in the process of constructing a CI

Question 10

Estimating Required Sample Size p̂

Answer 10

(p̂ known) n=(zα/2)^2p̂q̂/E^2 (p̂ unknown) n=(zα/2)^2*0.25/E^2

Question 11

n > 30

Answer 11

Doesn’t need to be normally distributed

Question 12

n <30

Answer 12

Needs to be normally distributed

Question 14

CI for x̄ requirements

Answer 14

1. Simple random sample 2. σ is known 3. normal dist. or n>30

Question 14

How to state 95% confidence

Answer 14

We are 95% confident the CI actually contains the true value of (pop statistic)

Question 15

Estimating μ when σ is unknown

Answer 15

Find df, Use (A3) to find tα/2, Find E μ+/-E

Question 16

Margin of Error (E) x̄ equation

Answer 16

E=zα/2*σ/✓n, x̄-E<x̄+E

Question 17

Estimating Required Sample Size μ σ is known

Answer 17

n=(zα/2*σ/E)^2

Question 19

Estimating μ when σ is unknown

Answer 19

Find df, Use (A3) to find tα/2, Find E μ+/-E

Question 20

How to tell how many tails?

Answer 20

Confidence level=2 tails

Question 21

Degrees of freedom (df)

Answer 21

sample values that can vary df=n-1

Question 22

Finding df

Answer 22

Find df, Use (A3) to find tα/2, α=1-level of confidence

Question 23

Why use tα/2 (student t distribution)?

Answer 23

Because pop SD is unknown (σ), we estimate it with (s) and make the CI larger.