Besides mean and median, how else can we describe the shape and spread of a data set? Describe how to sets of data, with the same number of elements, can have the same median and mean, but look different

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected