What is the 7th term in the geometric sequence in which a10 is 9 and a13 is -72?
a. 2b. - 1/8c. - 9/8d. 1/4

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