You work for an wholesaler that sells coffee to retail businesses. For each client, you have data on the total purchases made by the client (Purchases, measured in kilograms), the profit of each client (Turnover, measured in dollars), and the number of stores operated by each client (Stores, measured in number of stores).

A simple regression withPurchasesas the dependent variable andTurnoveras the independent variable was run, leading to the following fitted model:

Purchases(hat)=2826.84+5.26Turnover

A simple regression withPurchasesas the dependent variable andStoresas the independent variable was run, leading to the following fitted model:

Purchases(hat) =6590.34+441.85Stores

A multiple regression withPurchasesas the dependent variable andTurnoverandStoresas the independent variables was run, leading to the following fitted model:

Purchases(hat)=2639.25+5.29Turnover+90.46Stores

What is the estimated increase in the expected value ofPurchasesmeasured in kilograms associated with a 1 store increase inStoresholdingTurnoverconstant