If $\sum x _ { i } = 15 , \sum y _ { 2 } = 36 , \sum x _ { i } y _ { i } = 210 , \sum x _ { i } ^ { 2 } = 30 , \text { and } n = 20$

Multiple Choice

If $\sum x _ { i } = 15 , \sum y _ { 2 } = 36 , \sum x _ { i } y _ { i } = 210 , \sum x _ { i } ^ { 2 } = 30 , \text { and } n = 20$ then the least squares estimate of the slope coefficient $\beta _ { 1 }$ of the true regression line $y = \beta _ { 0 } + \beta _ { 1 } x$ is

A) 18.75
B) 28.42
C) 9.15
D) 9.76
E) 10.50