Chapter 13: Statistics
Mean, Median, and Mode of Grouped Data
This chapter focuses on calculating the central tendencies—mean, median, and mode—for grouped data. The mean is calculated using the direct method, assumed mean method, or step-deviation method, which simplify calculations based on the class intervals and frequencies. The mode represents the most frequently occurring value and is found using a specific formula that estimates the value within the modal class. The median is the middle value that divides the data into two equal parts, calculated using cumulative frequency and the median class.
Graphical Representation and Interpretation
Cumulative frequency tables and ogives (curved graphs) are used to represent and interpret data visually. By plotting cumulative frequencies against upper class boundaries, students learn to draw less than and more than ogives. The intersection point of both ogives helps visually estimate the median. These graphical tools are useful for analyzing data trends and understanding data distribution in a clear and comparative manner.
Applications and Problem Solving
Through various real-life examples—like student scores, temperatures, or income ranges—the chapter teaches how to organize data in frequency tables and apply statistical formulas accurately. It emphasizes interpreting results in context and comparing measures of central tendency to understand which one best represents the data. Exercises include word problems, data analysis, and estimating unknown values using statistical tools.