EDEXCEL GCSE FOUNDATION MATHS - What is Combined Mean

Edexcel GCSE Foundation Maths: Combined Mean

The combined mean is the average of two or more sets of data when they are combined. Here's how to calculate it:

1. Calculate the total sum of all data points.

• Multiply the mean of each set by the number of data points in that set.
• Add these products together.

2. Calculate the total number of data points.

• Add the number of data points in each set.

3. Divide the total sum by the total number of data points.

Example:

• Set 1: Mean = 10, Number of data points = 20
• Set 2: Mean = 15, Number of data points = 30

Step 1: Total sum = (10 * 20) + (15 * 30) = 200 + 450 = 650

Step 2: Total number of data points = 20 + 30 = 50

Step 3: Combined mean = 650 / 50 = 13

Therefore, the combined mean of the two sets of data is 13.

Here are some key points to remember:

• The combined mean is a weighted average, giving more importance to sets with a larger number of data points.
• This concept is useful when dealing with multiple groups of data that need to be analyzed together.
• You can use this formula to calculate the combined mean for any number of sets of data.

Practice Questions:

1. Two groups of students took a test. Group A had a mean score of 75 and 25 students. Group B had a mean score of 80 and 30 students. What is the combined mean score?

2. A company has two branches. Branch A has 50 employees with an average salary of £30,000. Branch B has 75 employees with an average salary of £35,000. What is the combined average salary for all employees in the company?

By understanding how to calculate the combined mean, you will be able to effectively analyze and compare different sets of data.