We can all calculate as we please.
So I'm not asking, and certainly not requiring, that you do it in any other way.
I was merely clarifying what you may have done because there was no way that I could tell that your options trade exactly covered the number of underlying shares of MU that you own.
For all I know, you may have 2,000 shares of MU and only traded one Call option. Or maybe you only have 50 shares of MU.
To nitpick, you should add the cost ($1.52 x 100) of your options to your $39.80 (cost of your 100 shares at trade entry, assuming matching number of shares). Then your option gain (relative to stock plus option) would be 2.86%.
I'll round that up to 3% to avoid further argument.