MATHS - Statistics - Missing Value When Mean Known

The video tutorial explains how to find a missing value when given the mean. It covers the concept of mean as a form of average, calculated by dividing the sum of values by their count. The tutorial demonstrates reversing this process using multiplication to find original values. A scenario involving students' test scores is used to illustrate calculating mean for different groups and the entire class. The use of tables to organize data and solve problems is emphasized, showing how to find unknown sums or counts. Practical examples are provided to reinforce understanding.

What is the mean, and how is it calculated?

• The mean is the difference between the highest and lowest values in a data set.

• The mean is a type of average found by dividing the sum of values by the number of values.

• The mean is the most frequently occurring value in a data set.

• The mean is the middle value in a data set, calculated by arranging numbers in order.

In the given scenario, how many students are there in total?

• 30 students

• 50 students

• 20 students

• 10 students

How can you find the total marks for the girls if you know the total marks for the boys and the class?

• Divide the class total marks by the number of girls.

• Multiply the boys' total marks by the number of girls.

• Subtract the boys' total marks from the class total marks.

• Add the boys' total marks to the class total marks.

What is the reverse process of division used to find a missing sum?

• Addition

• Subtraction

• Multiplication

• Division

How can you find the number of people if you know the sum and the mean?

• Add the sum to the mean.

• Subtract the mean from the sum.

• Divide the sum by the mean.

• Multiply the sum by the mean.