Testing significance of difference between two averages.

Hi all,

Firstly, I apologise if this is in the wrong section of the forum but I know absolutely nothing about math.

I've been asked to find several values between two mean velocities and figure out if the means are "significantly different":

- P value
- t value
- t crit value
- df

**Mean velocity A: 0.471m³/s**

Mean velocity B: 0.205m³/s

(These are the means of two data sets on Excel with 40 samples in each)

If anybody could shed some light as to what these are and how to calculate them, as simplified as possible, I'd be extremely grateful.

Thanks in advance,

OSNS