The insertion of a bubble chart requires you having your data laid out.
Your data would look something like this:
Begin with marking all the whole data.
On top, you should click on insert (1), and then click on the recommended chart (2).
Start with clicking on All Charts (1), then choose scatter (2), choose bubbles (3), and finally click ok (4).
Note: The size of bubbles are determined by the data. The bigger the values, the bigger the bubbles.
Note: You can customize the design as you wish, including the title.