Solution

import numpy as np

print(unlever(a[0],a[1],a[2],a[3]))
print(unlever(b[0],b[1],b[2],b[3]))
print(unlever(c[0],c[1],c[2],c[3]))
print(unlever(c[0],c[1],c[2],c[3]))
print("The average is:")
rates = []
rates.append(unlever(a[0],a[1],a[2],a[3]))
rates.append(unlever(b[0],b[1],b[2],b[3]))
rates.append(unlever(c[0],c[1],c[2],c[3]))
rates.append(unlever(c[0],c[1],c[2],c[3]))
print(np.mean(rates))
def WACC(price,outstanding,debtValue,debtYield,stockReturn,taxRate):
    equity = price*outstanding
    total = equity+debtValue
    return (equity/total)*stockReturn+(debtValue/total)*debtYield*(1-taxRate)
print("The WACC is:")
print(WACC(10.5,20,(300-200),.04,.1025,.2))

You should get 0.0797580645161.

Source Code