Chi-Square Test is almost completed.

The test can be calculated either directly from statistic table by unchecking "Calculate Statistic from Spreadsheet" checkbox. The user then can fill the table and can press Recalculate to find chi-square value.

An added functionality of "Export To Spreadsheet" is added. Using this, the user can export the statistic table to a spreadsheet. It also acts as an alternative method to save statistic table in some form (temporarily)

There is also a "Clear" button added in the "Statistic Table" Widget in GeneralTestView class. The button clears all the data in "Statistic Table" excluding the header data.

MyTableModel is subclassed from QStandardItemModel, to provide functionality for a user to edit headers. The headers can also be put into non-editable mode if required.