GRADE 12 – Unit 3: Statistics

In this unit of Grade 12 Maths Statistics, as part of the Ethiopian matric curriculum, we explore the concepts of statistics, which is the science of collecting, organizing, presenting, analyzing, and interpreting numerical data. The role of statistics is vital in drawing meaningful conclusions based on data, and its application spans across various fields such as business, meteorology, economics, social and political sciences, and education.

Statistics is used to make decisions, predict outcomes, and provide insights into numerous aspects of everyday life. This unit will help students understand the practical application of statistics, the importance of variability, and how to summarize data efficiently.

Previously, students have studied basic statistical concepts such as data collection, presentation, and measures of central tendencies—mean, median, and mode. They have also encountered the concept of measures of dispersion, which indicate how data values spread. These measures include range, variance, and standard deviation.

In this unit, we shall revisit these concepts and build upon them by introducing additional measures of dispersion, including:

Inter-quartile range
Mean deviation
Quartile deviation
Standard deviation

Furthermore, students will learn about relative measures of dispersion, which compare the variability of different datasets. These include the coefficient of range, the coefficient of quartile deviation, and the coefficient of mean deviation. Lastly, we will also cover sampling techniques, an important concept that allows us to make reliable inferences about populations based on smaller samples.