Sorry, \(\dfrac{a+b}{2}.\dfrac{b+c}{2}.\dfrac{c+d}{2}.\dfrac{d+e}{2}.\dfrac{e+a}{2}\ge\dfrac{a+b+c}{3}.\dfrac{b+c+d}{3}.\dfrac{c+d+e}{3}.\dfrac{d+e+a}{3}.\dfrac{e+a+b}{3}\)