The file P08_10.xlsx contains data on annual advertising (per capita) and annual unit sales (per capita) in different regions of the country. Determine an Sshaped curve as described by equation (8.1)...

The file P08_10.xlsx contains data on annual advertising (per capita) and annual unit sales (per capita) in different regions of the country. Determine an Sshaped curve as described by equation (8.1) that can be used to determine how advertising influences sales.