Mekko charts present data using variable width bars. They can display up to three levels of data in a two-dimensional chart. Mekko charts are useful in such areas as market analysis.
The combo chart allows you to combine the features of the bar chart with those of the line chart: you can show the values of one expression as bars while displaying those of another expression as a line or symbols.
Re: What is the Difference between Combo-Chart & Mekko-Chart?
Mekko Chart is similar to the stack bar chart but additionally it shows the relativity among the different stack categories with the increased or decreased width. This will help in identifying the strongness or weakness of a particular category.