from statistics import stdev

X = [95, 85, 80, 70, 60]
Y = [85, 95, 70, 65, 70]

n = 5
sdX = stdev(X)
sdY = stdev(Y)
meanX = sum(X)/len(X)
meanY = sum(Y)/len(Y)

PCC = (sum([(x-meanX)*(y-meanY) for x,y in zip(X,Y)]))/((n-1)*sdX*sdY)

b = PCC*(sdY/sdX)
a = meanY-b*meanX

print(round(a+b*80, 3))