print_mean_sd() has gap in "SD"

[m-Py]

print_mean_sd() has the form $(M = 5.50$, $SD = 3.03)$, which produces a small gap between S and D in SD. See:

We might just want to create:

(*M* = 5.50, *SD* = 3.03).

For Latex/PDF output, when sticking with $$, we would need to create:

$(M = 5.50$, $\mathit{SD} = 3.03)$  

But I think using ** works in this case?