Question

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: 2.79 2.53 2.78 3.79 2.33 2.72 3.88 4.15 3.79 4.43 3.47 4.47 2.50 3.61 2.77 3.53 3.07 (a) Calculate Σxi and Σxi2. (Round Σxi2 to two decimal places.) Σxi = mm2 Σxi2 = mm4

Answer 1

Σxi =56.61

Σxi²=196.23

Explanation:

X be the random variable represents area of scleral lamina (mm2) from human optic nerve heads

Σxi can be obtain by adding all x values

Σxi=2.79+2.53+2.78+3.79+2.33+2.72+3.88+4.15+3.79+4.43+3.47+4.47+2.5+3.61+2.77+3.53+3.07=56.61

Σxi =56.61

Σxi² can be obtained by squaring x values and then adding them.

Σxi²=2.79²+2.53²+2.78²+3.79²+2.33²+2.72²+3.88²+4.15²+3.79²+4.43²+3.47²+4.47²+2.5²+3.61²+2.77²+3.53²+3.07²=196.233

Σxi²=196.23