$2\mathrm{.}86pts$

Use the information given below to answer the seven $(23-29)$ questions that follow.

Northeastern Commerce Bank wants to analyze how does the income influence financing rates, a financing team recorded the average financing rate $(\%)$ and the average income of its customers in a local branch. A simple linear regression of the data follows $($partial output is shown$)$:

$1,2,3,4,5,6,7,8,9,10$

Income $(thousands)10\mathrm{.}6,13\mathrm{.}3,18\mathrm{.}5,11\mathrm{.}5,11\mathrm{.}7,20\mathrm{.}1,15\mathrm{.}5,15,11\mathrm{.}1,16\mathrm{.}7$

Financing Rate $(\%)$

$\backslash$table$[[8,8\mathrm{.}5,7\mathrm{.}6,8\mathrm{.}5,8\mathrm{.}9,7\mathrm{.}5,8\mathrm{.}8,8,7\mathrm{.}8,8\mathrm{.}4]]$