Mathematics (4024)
Mean: Add all values, divide by how many. Most common average. Median: Middle value when data is in order. Good when there are outliers. Mode: Most frequent value. Can be more than one. Range: Highest - Lowest. Measures spread.
Bar charts: comparing categories Pie charts: showing proportions (angles must add to 360°) Histograms: continuous data with unequal class widths Scatter graphs: showing correlation between two variables Cumulative frequency: finding median and quartiles
Probability = Number of favorable outcomes / Total outcomes P(event) is always between 0 (impossible) and 1 (certain) P(not happening) = 1 - P(happening) For independent events: P(A and B) = P(A) × P(B) For mutually exclusive events: P(A or B) = P(A) + P(B)
Topic 5 of 5Cambridge O Levels
Statistics & Probability
Analysing data and calculating chances
Statistics helps us collect, organise, and understand data. Probability tells us how likely events are.
Averages (Measures of Central Tendency):
Displaying Data:
Probability:
Key Points to Remember
- 1Mean = sum of values / number of values
- 2Probability = favourable outcomes / total outcomes
- 3P(not A) = 1 - P(A)
- 4Independent events: P(A and B) = P(A) × P(B)
Pakistan Example
PSL Cricket Stats
In PSL 2026, Babar Azam scored: 45, 82, 12, 67, 91, 34, 56 in 7 innings. Mean = (45+82+12+67+91+34+56)/7 = 387/7 = 55.3. Sorted: 12, 34, 45, 56, 67, 82, 91. Median = 56 (middle value). Range = 91-12 = 79 (shows inconsistency). A selector might prefer a player with a lower range (more consistent). The probability of him scoring 50+ is 4/7 ≈ 57%.