Can I auto select a radio button within the same question?

For example I have 5 options in the one radio button question(below):

Tackers

Dinghy

Keelboat

Powerboat

Windsurfing

If the user check Tackers, we want Dinghy to automatically select as well.

Hello YNSW,

Unfortunately it is currently not possible to setup conditions to update the selection of same checkbox question. I would suggest you to please use separate fields to show / hide conditions.

Alternative option is to download your form's full source code and add custom JavaScript code to achieve your requirement. Please be noted that if you download your form's source code and add custom script code, you will not be able to upload it back to JotForm but will have to host it yourself in your web server. 

Thank you!