[iamhasek]

If im supposed to calculate the mean speed of Helium and all Im given is the temperature, what formula(s) should i be using? :unsure:

[Demotivator]

If by mean you mean the average (not root mean squared) speed:
average speed = Sqroot[(8RT/(pi)M)]  meters per second.
M is molar mass in Kilograms, T is in Kelvin, R = 8.3145  N m