G1 = [68,75,70,75,78,72,72,66,71,72]
G2 = [74,74,68,62,66,78,66,69,75,60]
G3 = [70,79,66,70,80,64,69,72,71,69]
G4 = [58,62,58,62,60,67,70,60,63,60]

sum1=sum(G1)
sum2=sum(G2)
sum3=sum(G3)
sum4=sum(G4)
sum5=sum(G1)+sum(G2)+sum(G3)+sum(G4)

y1=sum1/10
y2=sum2/10
y3=sum3/10
y4=sum4/10
y5=sum5/40

jojo1=sum((G1-y1).*(G1-y1))
jojo2=sum((G2-y2).*(G2-y2))
jojo3=sum((G3-y3).*(G3-y3))
jojo4=sum((G4-y4).*(G4-y4))
jojo5=sum(jojo1+jojo2+jojo3+jojo4)

SSamong=10*(y1-y5)*(y1-y5)+10*(y2-y5)*(y2-y5)+10*(y3-y5)^2+10*(y4-y5)^2

SSwithin=jojo5

SStotal=SSamong+SSwithin