A study of the relationship between age and various visual functions (such as acuity and...

A study of the relationship between age and various visual functions (such as acuity and depth perception) reported the following observations on the area of scleral lamina (mm²) from human optic nerve heads (“Morphometry of Nerve Fiber Bundle Pores in the Optic Nerve Head of the Human,” Experimental Eye Research, 1988: 559–568):

a. Calculate ∑x_i and ∑x²_i.

b. Use the values calculated in part (a) to compute the sample variance s2 and then the sample standard deviation s.