Mean and Median Calculations
The mean (average) is your most reliable measure because it considers every single data point in your set. Use the formula X̄ = ΣX/n where you add up all values and divide by how many numbers you have. For example, with test scores 56, 35, 12, 20, 14, 28, 15, you'd get (56+35+12+20+14+28+15)/7 = 25.71.
The median finds the middle value and isn't easily thrown off by extreme scores. First, arrange your data in order from smallest to largest. Then use the formula n+1/2 to find which position holds your median.
With an odd number of data points, you'll get a whole number that points directly to your median. With an even number of data points, you'll get a decimal (like 3.5th position), which means you average the two middle values.
Pro Tip: Median is super useful when you have outliers - like if one person scored 100 while everyone else scored around 75, the median gives you a better picture than the mean.