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**zorro** Question : The failure rate of a certain electronic device is suspended to increase linearly with its temparature. Fit a least squares linear line through the data (two measurements were taken for each given temparature)

$\displaystyle

\begin{array}{c|c|c|c|c|c|c}

Temp \ F & 55 & 65 & 70 & 85 & 95 & 105 \\

\hline

Failure \ rate \ 10^6 & 1.90 & 1.93 & 1.97 & 2.00 & 2.01 & 2.01 \\

. & 1.94 & 1.95 & 1.97 & 2.02 & 2.02 & 2.04 \\

\end{array}$

i) Obtain desired least square line

ii) Obtain predicted failure rate at $\displaystyle 70^{\cdot} F$