Population vs Sample
Population: every member of a group.
Sample: a subset of member that time and resources allow you to measure.
The main 2 concepts often discussed for Measurements of Data
1. Measures of Central Tendency
This is divided into 3 categories
a. Mean: Its the average of numbers. (add up all the numbers, then divide by how many numbers there are)
b. Median: Its the middle value of numbers. (for odd numbers its n+1/2 )
c. Mode: Its the most occuring value.
2. Measures of Dispersion
This is divided into 3 categories
a. Range: its the difference between maximum value and minimum value.(max-min)
b. Variance: It is calculated as sum of square distance from each point to the mean → S² = Σ(x-x̄)²/(n-1)
c. Standard Deviation: Its the square-root of Variance — S = √(Σ(x-x̄)²/(n-1))