Finding what fraction of molecules have speeds over a certain value

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Erubus
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Homework Statement


A sample of oxygen gas with molar mass 32 g/mol contains 5.0 moles and is at a temperature of 500 K. How many moles of the gas have speeds between 375 m/s and 380 m/s?

Homework Equations


Maxwell Boltzmann Distribution:
f(v) = 4[itex]\pi[/itex][[itex]\frac{M}{2pi RT}[/itex]]^(3/2) * v^2 * e^[(-Mv^2)/(2RT)]

The Attempt at a Solution


I know that this function gives the probablility of having the molecules at some speed v, but I'm not sure how to translate this over a range or how to calculate the number of moles over this range.
 
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Do you know how to use the M-B distribution to find out how many molecules have a speed greater than 380 m/s?

Do you know how to use the M-B distribution to find out how many molecules have a speed greater than 375 m/s?