Estimate the number of florist businesses operating in Sydney using a transparent Fermi model. Then quote a two-sided market around your estimate and explain how model uncertainty determines the spread and how you would update after receiving a small piece of evidence. ### Constraints & Assumptions - No internet lookup is available during the estimate. - The goal is a defensible reasoning process, not knowledge of the true count. - State whether the geographic unit and business definition include suburbs, market stalls, and online-only sellers. ### Clarifying Questions to Ask - What boundary defines Sydney for this estimate? - Does one shop location count separately from one business? - What size can be traded and what loss tolerance should inform the market? ### What a Strong Answer Covers - A population-demand or neighborhood-density decomposition with explicit units. - Sanity checks using an independent route to the answer. - A central estimate and an uncertainty range tied to assumptions. - A bid and ask with correct orientation and a spread wide enough for the stated uncertainty. - A Bayesian-style update that changes the relevant assumption rather than arbitrarily moving the quote. ### Follow-up Questions - How would one observed suburb with 12 florists change the estimate? - Which assumption contributes most to variance? - How would your spread change after several correlated observations?