What is the eccentricity for this ellipse?

x^2/9+y^2/4=1

so a^2 = 9 ---> a = 3

b^2 = 4 ---> b = 2

for a horizontal ellipse like the given,
b^2 + c^2 = a^2
4 + c^2 = 9
c^2 = 5
c = √5

e = c/a = √5/3 or appr .745