Experimental Probability

This lesson covers experimental probability (relative frequency), estimating expected outcomes from experiments, comparing theoretical and experimental probability, and identifying bias. These topics are part of the Edexcel GCSE Mathematics (1MA1) specification and can appear on any of the three papers.

---

Relative Frequency

Relative frequency is the proportion of times an event occurs in an experiment. It is an estimate of the probability based on collected data rather than equally likely outcomes.

Relative frequency of event A = number of times A occurs / total number of trials

Relative frequency is also called experimental probability or estimated probability.

Worked Example 1

A drawing pin is dropped 200 times. It lands "point up" 72 times. Estimate the probability that the drawing pin lands point up.

Solution: Relative frequency = 72/200 = 0.36

Key Point: Relative frequency is an estimate of probability, not the exact probability. The more trials you carry out, the more reliable the estimate becomes.

---

Key Vocabulary