Statistical measures help us summarize and understand data sets through measures of central tendency and spread.
Mean (x̄): Sum ÷ Number of values
Median: Middle value when ordered
Mode: Most frequent value
Range: Highest - Lowest
Quartiles: Q1, Q2 (median), Q3
Standard Deviation: Measure of spread
Data: 65, 70, 75, 80, 85, 90, 95
Mean: (65+70+75+80+85+90+95) ÷ 7 = 560 ÷ 7 = 80
Median: Middle of 7 values = 80
Mode: No repeated values = None
Range: 95 - 65 = 30
Q1: 25th percentile = 70
Q2: 50th percentile (median) = 80
Q3: 75th percentile = 90
IQR: Q3 - Q1 = 90 - 70 = 20
Dataset: 12, 15, 18, 15, 21, 24, 15, 18
Question 1: What is the mean of this dataset?
Question 2: What is the median of the same dataset?
Hint: First order the values: 12, 15, 15, 15, 18, 18, 21, 24
Question 3: What is the mode of the dataset?