A sociologist reviews randomly selected surveillance videos from a public park over a period of several years and records the amount of time people spent on a smartphone. The statistical procedure the sociologist used is called...

an observational study.

Step-by-step explanation:

An observational study can be defined as a type of study in which a researcher observes and measures the effect of a diagnostic test, risk factors, or treatments on individuals without intervening, changing or manipulating who are or aren't exposed to it (controlled conditions).

In this scenario, a sociologist reviews and analyzes a public park surveillance videos that were randomly selected over a period of several years. From the data obtained, he records the amount of time people spent on a smartphone. Thus, the statistical procedure the sociologist used is called an observational study because he doesn't interfere or manipulate the surveillance video containing information about the amount of time people in the public park spent on their smartphone.

Additionally, an unobtrusive data collection is a data collection technique used mainly in the social sciences to obtain or gather data without the researcher directly interfering or interfacing with the subject being studied. Thus, it doesn't influence the behavior, action or response of the subjects under study.

a is the correct

answer: 414,377,008

step-by-step explanation:

just multiply it