Given a dataset XXX with n=20n=20n=20, ∑i=120xi=100\sum_{i=1}^{20} x_i = 100∑i=120xi=100, and ∑i=120xi2=800\sum_{i=1}^{20} x_i^2 = 800∑i=120xi2=800. Calculate the sample variance s2s^2s2.
252525
26.3226.3226.32
353535
36.8436.8436.84