Chapter 7: Sampling Distributions

Question 1

Sampling error

Answer 1

= I samples statistic - population parameter I

refers to the variation in sampling statistics that arise from chance alone

Question 2

Point Esimator

Answer 2

a sample statistic that is used to estimate a population parameter

Question 3

Sampling Distribution

Answer 3

the probability distribution of a sampling statistic

Question 4

Standard Error

Answer 4

the standard deviation of a sampling distribution

Question 5

Expected Value of the Sample Mean

Answer 5

= population mean

So the sample mean is a unbiased estimator of the population mean

Question 6

“Show the Sampling Distribution”

Answer 6

1. Expected Value
2. Standard Error
3. Normality

Question 7

Central Limit Theorem

Answer 7

the sampling distribution of any statistic will be normal if the sample size is large enough

Question 8

Normality for the Sampling Distribution of the Mean

Answer 8

1. n ≥ 30
2. the underlying population is normal

Must be normal to use the standard normal distribution (Z-Table)

Question 9

Rule for Underlying Population Normality

Answer 9

Within +/- 3 time the standard error of skewness

Question 10

Normality for the Sampling Distribution of the Proportion

Answer 10

n(p) ≥ 5 and (n)(1-p) ≥ 5

Must be normal to use the standard normal distribution (Z-Table)

Question 11

Relationship between sample size and standard error of the mean

Answer 11

As sample size increases, standard error of the mean decreases

Question 12

Expected Value of the Proportion

Answer 12

= population proportion

so the sample proportion is an unbiased estimator of the population proportion