.=(A1 + A2 + A3)/3 (or) = Average (A1 : A3) = 62.7%

(i) Inserting a Column : In Calc, we can insert a new column anywhere in the worksheet.
Step 1 : Select the column where a new column should be inserted.
Step 2 : Right-click on the selected column name that you have selected. A pop up menu appears.
Step 3 : click the "Insert Columns" option from the menu.
Now, a new column will be inserted to the left of the current column. A new column can also be inserted using Insert \(\rightarrow\)Columns command.
(ii) Inserting Rows : In Calc, we can insert a new row anywhere in the worksheet.
Step 1: Select the row where a new row is to be inserted.
Step 2: Right-click on the row number, a pop-up menu appears
Step 3 : click "Insert Rows" option from the menu.
Now, a new row will be inserted above the current row. Insert \(\rightarrow\)Rows command is used to insert a new row.

(i) OpenOffice Calc is a popular open source spreadsheet application maintained by Apache Foundation.
(ii) Calc is the spreadsheet component of OpenOffice. You can enter any kind of data in a spreadsheet and then manipulate this data to produce certain results.
(iii) Alternatively, enter data and then use Calc in a 'What If..' manner by changing some of the data and observing the results without having to retype the entire spreadsheet.