Parenting Shape Keys Together

How exactly would one go about parenting two shape key values together? For example: When shape key ‘a’ for object ‘one’ is set to 0.6 I want shape key ‘b’ for object ‘two’ to be set to 0.6 as well. Thank you in advance for any light you may shed on this subject.

You want to use a driver to do this. A quick youtube search should get a number of tutorials on drivers.

Good luck!