Chapter 1 - Section 1.12 - Modeling Variation - 1.12 Exercises - Page 129: 48

a) $S=\dfrac{kN}{n}$ b) $k =18$ lb/oz c) $36$lb

a) As per the given problem, we have: $S=\dfrac{kN}{n}$ Here, $k$ is defined as constant of proportionality b) From part (a), we have $S=\dfrac{kN}{n}$ Plug the given data in the above expression, we get $30=k\dfrac{20}{12} \implies k =18$ lb/oz c) From part (a), we have $S=\dfrac{kN}{n}$ Then, $S=(18)\dfrac{10}{5}=36$lb