The fatigue data for a ductile cast iron are given

The fatigue data for a ductile cast iron are given as follows:

(a) Make an S–N plot (stress amplitude versus logarithm cycles to failure) using these data.
(b) What is the fatigue limit for this alloy?
(c) Determine fatigue lifetimes at stress amplitudes of 230MPa (33,500psi) and 175MPa (25,000psi).
(d) Estimate fatigue strengths at 2 ( 105 and 6 ( 106cycles.