Lecture 5

Question 1

Sample

Answer 1

a subset of the population

Question 2

aims of sampling

Answer 2

• reduce cost
• reduce time
• generalize about the populations

Question 3

Random sample

Answer 3

Each element in the population should have an equal chance of being selected

Question 4

Nonrandom samples

Answer 4

Non-random samples are almost certainly biased

Question 5

sampling distribution

Answer 5

A sampling distribution is the probability distribution of a given statistic based on a random sample

Question 6

Sampling distributions - unbiasedness

Answer 6

the expected value of a point estimator equals the population parameter, then the point estimator is unbiased. This means that we do not constantly overestimate or underestimate the population parameter using this point estimator.

Question 7

the central limit theorem

Answer 7

When using large n, then X flatroof is approximately normally distributed due to the central limit theorem