The LP problem whose output follows determines how many necklaces, bracelets, rings, and earrings a jewelry store should stock. The objective function measures profit; it is assumed that every piece stocked will be sold.

Constraints measure display space in units, time to set up the display in minutes and two marketing restrictions.

MAX $\{\begin{array}{c}\text{:}[100N+120B+150R+125E]\\ N+2B+2R+2E108& \text{S}\text{p}\text{a}\text{c}\text{e}& \\ 3N+5B+E120& \text{T}\text{i}\text{m}\text{e}& \\ N+R,& 25\text{M}\text{a}\text{r}\text{k}\text{e}\text{t}\text{R}\text{e}\text{s}\text{t}\text{r}\text{i}\text{c}\text{t}\text{i}\text{o}\text{n}& 1\\ B+R+E50& \text{M}\text{a}\text{r}\text{k}\text{e}\text{t}\text{R}\text{e}\text{s}\text{t}\text{r}\text{i}\text{c}\text{t}\text{i}\text{o}\text{n}& 2\end{array}$

Use the output below to solve and answer the following question.

By how much can the profit on rings increase before the solution would change?

$\backslash$table$[[$Variable Cells$],[,,$Final,Reduced,Objective,Allowable,Allowable$],[$Cell$,$Name,Value,Cost,Coefficient,Increase,Decrease$],[$$B$$18,$Necklace,$8,0,100,1E+30,12\mathrm{.}5],[$$C$$18,$Bracelet,$0,-5,120,5,1E+30$