A beam subjected to axial loading will experience an axial stress, ${}_a.$ If$,$ in addition, the beam is subjected to a bending load, a bending stress, ${}_b,$ will also occur at the outer fibers $($top and bottom surfaces$)$ of the beam. The maximum stress at the outer fibers of the beam will be ${}_{\text{m}\text{a}\text{x}}={}_a+{}_b.$ Assume that ${}_a$ and ${}_b$ are independent.

Given: $\frac{?}{\text{b}\text{a}\text{r}}({)}_a=80\mathrm{.}0$MPa,hat$({)}_{{}_a}=8\mathrm{.}00$MPa$\frac{,}{b}ar({)}_b=379\mathrm{.}0$MPa, and hat$({)}_{{}_b}=19\mathrm{.}90$MPa.

The rod is made of a steel with $\frac{?}{\text{b}\text{a}\text{r}}(S{)}_y=553$MPa and hat$({)}_{S_y}=42\mathrm{.}7$MPa. Assuming the strength and stresses have normal distributions, determine the design factor and the reliability guarding against yielding.

The design factor is $($Round the final answer to three decimal places.$)$

The reliability guarding against yielding is $\%.$