For the timing belt of a car, let the failure rate=(x) and the lifetime=x (mileage for the car). The reliability function is given by R(x)=R(0). Find

1. The probability density function of the time to failure f(t) and failure rate (x).
2. Is (x) a DFR, CFR or IFR and why?
3. Can you assume R(0)=1.0 and why? What type of distribution the failure time (mileage) has? The scale parameter=? and shape parameter =?
4. R(100)=? and MTTF=?
5. If you want the reliability, or probability that the timing belt is not broken on the road, to be at least 0.70 or 70%, by what mileage should the timing belt be changed?