Let's break down the problem and solve step by step. ### Step 1: Understand the Problem - Views in 2021: **1,600 million** - Views in 2022: **2,300 million** - Surgeries in 2022: **120,000** - You are asked: Given the "marginal effect from above," find the number of surgeries in 2021. **But**: You haven’t specified the "marginal effect from above" in your message. Usually, "marginal effect" refers to how much the number of surgeries changes per million views. Let's denote this as \( m \) (number of surgeries per million views). ### Step 2: Set Up the Equation Let: - \( S_{2021} \): Number of surgeries in 2021 (unknown) - \( S_{2022} = 120,000 \) - \( V_{2021} = 1,600 \) million - \( V_{2022} = 2,300 \) million - \( m \): Marginal effect (number of surgeries per million views) The change in the number of views = \( V_{2022} - V_{2021} = 2,300 - 1,600 = 700 \) million views The change in number of surgeries = \( S_{2022} - S_{2021} \) If we assume the increase in surgeries is entirely due to the increase in views, then: \[ S_{2022} - S_{2021} = m \times (V_{2022} - V_{2021}) \] \[ S_{2022} - S_{2021} = m \times 700 \] ### Step 3: Solve for \( S_{2021} \) \[ S_{2021} = S_{2022} - m \times 700 \] ### Step 4: Plug in the Marginal Effect **You need to provide the value of \( m \), the marginal effect, for a numerical answer!** #### If you provide \( m \): Suppose, for example, the marginal effect \( m = 20 \) surgeries per million views. Then, \[ S_{2021} = 120,000 - 20 \times 700 = 120,000 - 14,000 = 106,000 \] --- ## **Final Answer (in terms of marginal effect \( m \)):** \[ \boxed{ \text{Number of surgeries in 2021} = 120,000 - 700 \times m } \] where \( m \) is the marginal effect (number of surgeries per million views). **If you give the value of the marginal effect, I can compute the exact number for you!**