Help with assignment

[dxfrelince]

heating_data = [[50,15,25,10],[100,13,65,15],[25,32,67,80]]
for i in range (len(heating_data)):
    m1 = heating_data[i][0]
    t1 = heating_data[i][1]
    t2 = heating_data[i][2]
    s = heating_data[i][3] 
    C = 4.19
    Q = m1*C*(t2-t1)
    energy = Q*(2.7778*10**-7)
    price = energy * s
    print ([[m1,t1,t2,s,Q,energy,price]])

energi_cost = [[Q,energy,s],[Q,energy,s],[Q,energy,s]]
energi_cost = [i][0]
energi_cost = [i][1]
energi_cost = [i][2]

print(energi_cost)

round (energy,3)
round (price,2)

Output:
  File "<ipython-input-39-696429c3a249>", line 14, in <module>
    energi_cost = [i][1]

IndexError: list index out of range