Statistics 1 (S1) Past Papers
Master Edexcel IAL Statistics 1 with organized past paper questions covering probability and data analysis.
5
Topics
12
Years
2014–2025
Coverage
Topics
Data Representation
Measures of Location and Spread
Probability
Correlation and Regression
Discrete Random Variables
FAQ
What is the formula for standard deviation?
Standard deviation σ = √[Σ(x-μ)²/n] or σ = √[Σx²/n - (Σx/n)²]. For sample standard deviation, use (n-1) in the denominator instead of n.
How do you calculate correlation coefficient?
PMCC (r) = Sxy/√(Sxx × Syy), where Sxy = Σxy - (ΣxΣy)/n, Sxx = Σx² - (Σx)²/n, Syy = Σy² - (Σy)²/n. r ranges from -1 to +1.
What's the difference between correlation and regression?
Correlation measures the strength of linear relationship between two variables (-1 to +1). Regression finds the equation of the line of best fit to predict y from x (y = a + bx).
How do you find E(X) and Var(X)?
E(X) = Σx×P(X=x) (sum of each value times its probability). Var(X) = E(X²) - [E(X)]² = Σx²×P(X=x) - [E(X)]².
When do you use P(A∩B) vs P(A∪B)?
P(A∩B) = probability of A AND B both happening. P(A∪B) = probability of A OR B (or both). P(A∪B) = P(A) + P(B) - P(A∩B).