Let X1,X2,…,X40X_1,X_2,\dots,X_{40}X1,X2,…,X40 be IID random variables with E[X1]=2\mathbb{E}[X_1] = 2E[X1]=2, E[1S20]=110\mathbb{E}\left[\dfrac{1}{S_{20}}\right] = \dfrac{1}{10}E[S201]=101. Define Sn=X1+⋯+XnS_n = X_1 + \dots + X_nSn=X1+⋯+Xn. Compute E[S40S20]\mathbb{E}\left[\dfrac{S_{40}}{S_{20}}\right]E[S20S40].