Need Help : group_by and summarize_each

I’m afraid I’m not quite sure what you mean. If you’re still trying to solve the same problem, the best thing you can do is post all of the code you are running. Excerpts of code really aren’t very helpful, since errors are usually due to the interaction of different parts.

Have you seen our guidelines for posting code-related questions here? FAQ: Tips for writing R-related questions

Also, since you said you had an Excel background, it occurred to me that this book might help you. It is currently available as a free preview in advance of publication:

It covers the general kind of thing you’re trying to do in some detail.