Estimation
How well can we guess a particular quantity
Statistics
Study of estimation and inference
Inference
Based on our estimated quantity, what kind of decisions can we make and how confident can we be in those decisions
Unit, individual, element, case
An object or person on which measurements are taken
Ex. A single can of dog food
Population
The set of all units of interest
Ex. All cans of dog food that could ever be created by this manufacturing process at this facitlity
Types of population
Finite or infinite
Infinite population
Not a finite amount
Ex. A dog food factory. No way to know how many cans they can make
Finite population
A set number of population
Ex. The set of all Canadian citizens at 7:30am June 10 2024
Sample
A set of units chosen from the population
Ex. 100 cans of dog food
Sample size
What is it and what symbol
Number of units in the sample
Symbol lower case n
n=100
Population size
What and what symbol
Number of u it’s in the population
Capital N symbol
Ex. N=infinity
Statistic
Characteristic of a sample
Ex. Sample mean weight = 140g
Parameter
Characteristic of a population
Ex. Population mean weight of all cans of dog food
How to type x bar in word
Insert -> equation -> type \bar{ -> hit space bar
A square with dots around it should appear with a horizontal line over top
Backspace to remove the {
Then highlight the square and type x
What does x bar mean
Mean
How to calculate mean in excel
=AVERAGE( typ numbers or the cells in here)
Population mean symbol
Mu
The u with a tail on front
Same symbol for micro
Population mean vs sample mean
The average of the whole population
Vs average of the sample
1-N vs 1-n
Sample subset of
A population
Sampling bias
An effect in which some units in the population have a higher chance of being selected in the sample than other
Convenience sample
Picking the easiest things
Ex. Pick the 1st three zucchini plants bc they were closest
Simple random sampling
Each unit in the population has an equal chance to be selected and that probability is
1/N
Ex. Picked from everyone in Canada you have 1/37000000 of being picked
Simple random sample no replacement
Simple random sample which each population unit may only be chosen once
Simple random sampling with replacement
Simple random sample which each population unit may be chosen more than once
Ex. Population 1-10
Sample 1,1,5,7
