Mean of a Grouped Data

This item is taken from IGCSE Extended Mathematics (0580) exam Paper 41 of June 2010.

To deal with this item, let us summarize the details of the problem:
   (a) Syllabus area: Statistics
   (b) Specific topic: Mean of Grouped Data
   (c) Formula Needed: 

Before we could get the mean, let us determine first the mid-interval values of each class.

Here is the summary of the classes with their corresponding mid-interval values and frequencies.

You can now find the mean using the formula above.

Another way of presenting the solution is through the use of a table for finding the mean.

From the table, we can directly calculate the value of the mean.

Therefore, the mean of the 60 potatoes is 32.5.

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