Extrapolate the number of shops in a city based on primary research

Hello All,

I am currently working on a project and need help as I am not strong with stats but need to extrapolate the number of shops based field research that has gathered a rough number of shops per area.

We have gathered primary data for the number of retail shops in Mumbai,India. Not all shops are available via google so we have collected the number of shops by walking the streets and plotted them on maps. We now know a rough estimate of the number of shops for certain areas but want to extrapolate the number of shops for the rest of the city.

Is there a specific way to go about this? If so, please use layman terms in your explanation and pretend I am a 5 year old.

Thanks for any help!