Astudy 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: 2.79 2.57 2.73 3.75 2.27 2.75 4.00 4.22 3.88 4.35 3.41 4.57 2.38 3.73 2.75 3.47 3.06(a) calculate ? xi and ? xi2. (round ? xi2 to two decimal ) use the values calculated in part (a) to compute the sample variance s2 and then the sample standard deviation s. (round your answers to three decimal places.)