A school teacher wants to analyse results. Identify the appropriate statistical technique to be used along with its justification for the following cases:
Teacher wants to compare performance in terms of division secured by students in Class XII A and Class XII B where each class strength is same.
Mode is the appropriate statistical technique. Since divisions (First, Second, Third) are categorical data, Mode helps identify the most frequently occurring division in each class. By comparing the modes of both classes, the teacher can determine which division is most common in each class and compare the overall performance pattern between Class XII A and Class XII B.
Teacher has conducted five unit tests for that class in months July to November and wants to compare the class performance in these five months.
Mean is the appropriate statistical technique. Since the teacher wants to compare class performance across five unit tests conducted in different months, Mean provides the average score for each month. By calculating and comparing the mean scores of July through November, the teacher can analyze how the class performance has varied across these five months and identify trends in performance.
Explanation
This question tests understanding of when to apply different statistical techniques. For part (a), divisions are categorical data (not numerical), so Mode is appropriate to find the most common category. For part (b), test scores are numerical data, and Mean is used to compare average performance across multiple time periods. The textbook context shows similar comparison problems in the table where Mean is used for comparing heights and incomes of residents between cities.