Statistics and probability

Statistics answers "what is typical": mean, median (middle of the row), mode (most frequent). Grades 2,3,3,4,5: mean 3.4, median 3. Probability is a chance from 0 to 1: heads on a coin = 1/2, six on a die = 1/6. Multiply independent chances: two heads in a row = 1/4.

• ●Mean: add everything, divide by count
• ●Median: sort and take the middle
• ●Chance: favorable ÷ all outcomes