Astudy of the relationship between age and various visual functions (such as acuity and depth percep-tion) reported the following observations on area of scleral lamina (mm2) from human optic nerve heads( morphometry of nerve fiber bundle pores in the optic nerve head of the human, experiment. eye res., 1988: 559—568): 2.75 2.62 2.74 3.85 2.34 2.74 3.93 4.21 3.884.33 3.46 4.52 2.43 3.65 2.78 3.56 3.01a. calculateσxi and σ 2/1b. use the values calculated in part (a) to compute the sample variance s^2 and then the sample stan-dard deviation s. reconsider the data on area of scleral lamina given abovea. determine the lower and upper fourths. b. calculate the value of the fourth spread. c. if the two largest sample values, 4.33 and 4.52, had instead been 5.33 and 5.52, how would this affectf f^s? explain. d. by how much could the observation 2.34 be increased without affecting f^s? explain. e. if an 18th observation, x18 =4.60, is added to the sample, what is f^s