GCSE Secondary Maths Age 13-17 - Probability & Statistics: Estimate of the mean - Explained

The video tutorial explains how to estimate the mean time for runners using a grouped frequency table. It emphasizes the importance of using mid values for calculations, a concept previously encountered in frequency polygons. The process involves calculating mid values for class intervals, multiplying these by their respective frequencies, and summing the results. The mean time is then found by dividing the total by the number of runners. The tutorial also outlines the marking scheme, highlighting common errors such as not using mid values, which can lead to accuracy issues.

What is the primary concept to focus on when estimating the mean time from a grouped frequency table?

• Using the total frequency

• Using the highest value

• Using the mid value

• Using the lowest value

How do you determine the mid value for a class interval of 60 to 90?

• By adding 60 and 90

• By subtracting 60 from 90

• By averaging 60 and 90

• By multiplying 60 and 90

What is the next step after calculating the mid values in the estimation process?

• Add all mid values together

• Subtract the smallest mid value from the largest

• Multiply each frequency by its mid value

• Divide each mid value by the frequency

How is the mean time calculated after obtaining the total sum of frequency times mid values?

• By subtracting the smallest frequency from the total sum

• By dividing the total sum by the number of class intervals

• By dividing the total sum by the number of runners

• By multiplying the total sum by the number of runners

What is a common mistake students make that leads to losing marks in this problem?

• Not using the total frequency

• Not using the mid value

• Not using the highest value

• Not using the lowest value