4.82 mL of a 0.262 M NaOH solution reacts completly with 4.79 mL of HCl solution according to the balanced chemical reaction shown below:

HCl (aq) + NaOH (aq) -> NaCl*aq) + H2O (I)

What is the molarity of the HCl solution?

4.82 x (1L/1000 mL) = .00482L
4.79 x (1L/1000 mL) = .00479L

(.00482L)(0.262M) = .00126284

(.00126284M/.00479L) = .263 M HCl

I was wondering if I set up and solved this problem correctly?

2 answers

The set up looks ok. I don't think you rounded properly. I get 0.26364 M which I would round to 0.264 M.
By the way, just as a shortcut, when everything is listed in mL, you need not change everything to L.
Ml x M = mL x M.
L x M = moles
mL x M = millimoles.