UNIT OVERVIEW

Statistics is about finding patterns in data and understanding how data values vary. You use statistics whenever you check your phone battery usage, track your marks over time, or see trends in the news.

In this unit, you will learn to:

• Draw and interpret histograms and frequency polygons from grouped data
• Construct and read ogive (cumulative frequency) curves to find medians and percentiles
• Calculate variance and standard deviation of ungrouped data using your calculator
• Interpret symmetric and skewed distributions
• Identify outliers using the IQR method and box-and-whisker diagrams
• Apply statistical concepts to solve real-world problems

Why statistics matters:

• Healthcare: Hospitals track patient waiting times using histograms to allocate staff better.
• Sports: Cricket analysts use standard deviation to measure how consistent a batsman is.
• Business: Shops analyse sales patterns to know when to stock more products.
• Education: Universities use cumulative frequency curves to set fair grade boundaries.

---