From the plot of yield strength versus $($grain diameter$)-1/2$ for a $70$ Cu$-30$ Zn cartridge brass, shown in Animated Figure $7\mathrm{.}15$ do the following:$($a$)$ Determine the value of the constant do of Equation $7\mathrm{.}7.$iMPa$($b$)$ Determine the value of the constant ky of Equation $7\mathrm{.}7.$iMPa$-($mm$)1/2($c$)$ Predict the yield strength of this alloy when the average grain diameter is $7\mathrm{.}4\backslash$times $10-3$ mm$.$iMPa