A coffee shop buys $350$ bugs of their most popular coffee beans esch morith. The cost of ordering and reseiving shipments is $$8\mathrm{.}50$ per ertier. Aocounting estimates antual carrying costs are $10$ cernts or $$0\mathrm{.}10$ per item per year. The supplier lead fime is $4$ operating flays. The shep epea ahos ou a to demand uniderisinty the company wishes to carry an extra supply of $10$ bags. Please keep two docimal places its your calculations. How many operating days will elapse on average between two consecutive orders?