Calculating Static Frictional Force on an incline

1. The problem statement, all variables and given/known data
A car (m = 1680 kg) is parked on a road that rises 17° above the horizontal. What are the magnitudes of (a) the normal force and (b) the static frictional force that the ground exerts on the tires?

2. Relevant equations
FsMAX = Mu*FN or in this case: FsMAX = Mu*mg*cos(17)

3. The attempt at a solution
I found (a), the normal force by finding mg (1680 * 9.8) and then multiplying that by cos(17) because of the incline. My problem is finding the static frictional force because there is no coefficient given. I’ve tried to find the coefficient by using the normal force, but I still end up with two unknowns… 16464 (FN) = Fs/Mu.

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