lecture six (sampling)

Question 1

what is sampling ?

Answer 1

it is essential for data collection in business analysis.

Question 2

Method of sampling

Answer 2

surveys
observation
interviews

Question 3

The goal of sampling

Answer 3

To minimise bias to ensure findings can be generalised to the entire population.

Question 4

population and sampling

Answer 4

population: the entire group of interest

sample: A subset selected from the population

Question 5

what is a good sample ?

Answer 5

A good sample should be representative of the population to avoid bias.

Question 6

population parameters vs sample statistics

Answer 6

parameters: characteristics of the population.

statistics: calculated features from the sample that help estimate the population parameters.

Question 7

What are point estimates ?

Answer 7

A single value used to estimate a population parameter.

Question 8

What are interval estimates ?

Answer 8

A range of values used to estimate a population parameter, accounting for potential errors.

Question 9

Normal distribution

Answer 9

A bell shaped curved that represents data distribution.

Question 10

What are the key properties of normal distribution ?

Answer 10

most values are closed to the mean (averages)

68% of the data is within 1 step of the mean
95% is within 2 steps (wider range)
99.7% is within 3 steps, covering almost all data.

Each steps refers to 1 standard deviation, which measures the data is.