Chapter 7

Question 1

Simple Random Sample

Answer 1

every member of the population has an equal chance of being selected
1/N

Question 2

Stratified Random Sample

Answer 2

divide the population into mutually exclusive groups and randomly sample from each group
-bigger group, bigger sample from that group

Question 3

Systematic Sampling

Answer 3

selecting every kth member of the population

K= N/n Take every 10th student

Question 4

Cluster Sampling

Answer 4

randomly selecting clusters as samples

• states
• mini snapshots

Question 5

Sampling Error

Answer 5

difference between the statistic and parameter
x ̅ - μ
-control by increasing sampling size

Question 6

Coverage Error

Answer 6

error in sampling frame

Question 7

Non-Response Error

Answer 7

failure to obtain responses from samples

Question 8

Measurement Error

Answer 8

error in responses of the samples

Question 9

Sampling Distribution: If the sample drawn is normal

Answer 9

the sample mean will also follow a normal distribution. x ̅~normal (μ=μ_x ̅ ,σ_x ̅ =σ/√n)

Question 10

Sampling Distribution: If the sample drawn has an unknown distribution

Answer 10

use the central limit theorem

Question 11

Central Limit Theorem

Answer 11

the sample mean will be approximately normal for n ≥ 30
x ̅~approximately normal(μ=μx ̅ ,σx ̅ =σ/√n)
P(x ̅<(a-μx ̅ )/σx ̅ )