Please help with part D, all needed information is given below. I was given nothing else

   

The zipper model is a cooperative model for helix-coil transitions. Here we demonstrate an important feature of this model, i.e. that once helix become energetically favored over coil, long runs of helix are favored over shorter runs. Part A For N=30, s=1.5 and = 0.001 calculate the partition function = 1726 90 Submit Previous Answers Part B Correct Calculate the probability that a peptide for which N=30 has a helical length of k=20. Assume s=1.5 and = 0.001 Pk-20 = 0.021 Submit Previous Answers Correct