Q: How can I respond to a reviewer comment about an error in the data?

I have received notification of moderate revision from a journal. In my submitted manuscript I had an error and presented a wrong value for a parameter that I calculated (In other words, my calculation was correct but I used a value from another time period; for example I stated 200 instead of say 400). I did not recognize the error until one of the reviewers highlighted it and asked how was the value so low. So I am wondering how do I proceed to answer to the reviewer comment. Would it create any doubts in the credibility of my submitted manuscript? In fact, the (value for the) parameter was not needed or used anywhere in the manuscript and was just referenced to show the environmental conditions. It can thus be deleted, which i am/was planning to do in the revision, but I am now wondering if it would impose some doubt if I proceed to delete it. Guidelines on how to respond will be greatly appreciated. Thanks in advance.