In [1]:

    

import numpy as np


    

In [2]:

    

x = [2,4,6,8]
y = [81, 93, 91, 97]


    

In [3]:

    

mx = np.mean(x)
my = np.mean(y)


    

In [4]:

    

print(mx)


    

    




5.0

In [5]:

    

print(my)


    

    




90.5

In [6]:

    

divisor = sum([(mx - i)**2 for i in x])


    

In [39]:

    

def top(x, mx, y, my):
    d = 0
    for i in range(len(x)):
        d += (x[i] - mx) * (y[i] - my)
    return d


    

In [40]:

    

print(x)


    

    




[2, 4, 6, 8]

In [41]:

    

dividend = top(x, mx, y, my)


    

In [42]:

    

print(dividend)


    

    




46.0

In [14]:

    

def top2(x, mx, y, my):
    return sum([((x[i] - mx) * (y[i] - my)) for i in range(len(x))])


    

In [15]:

    

print(top2(x, mx, y, my))


    

    




46.0

In [19]:

    

[((x[i] - mx) * (y[i] - my)) for i in range(len(x))]


    

    
Out[19]:





[28.5, -2.5, 0.5, 19.5]

In [43]:

    

a = dividend / divisor


    

In [44]:

    

b = my - (mx * a)


    

In [46]:

    

print(a,b)


    

    




2.3 79.0

In [ ]: