Data management exam

Permutations

When order matters

Ex: passwords

Combinations

When order does not matter

Ex: group of people

What are the key characteristics of a binomial distribution?

There are a certain number of independent trials and 2 possible outcomes for each trial (success or failure) with the probability being constant in each trial

Ex: counting the number of times a 1 is rolled in 10 rolls of a dice

Ex2: counting the times a coin lands on tails

What are the key characteristics of a hypergeometric distribution?

There are a certain number of dependent trials, choosing from a certain number of desirable items and leaving the rest of the trials to be chosen from undesirable items

Ex: counting the number of clubs dealt into a hand of 5 cards from a standard deck

What makes something a fair game?

The game must = 0

Systematic sample

Members are selected from the population at regular intervals

Stratified sample

Divides population into groups according to characteristics and selects members from each group appropriately

Simple random sample

Randomly select individuals/ items to study

Cluster sample

Divides population into groups and then randomly selects certain groups to study every member in the group

Convenience sample

Sample selected because it is easily accessible

Judgement sample

Uses researchers knowledge to select individuals/items

Voluntary sample

Participation is at the discretion of the respondent