Ais a survey that focuses on only a small portion of the population, and the results are generalized for the larger population.
a. sample
b. questionnaire
c. census
d. tally

A "sample" is a survey that focuses on only a small portion of the population, and the results are generalized for the larger population.

A sample survey is a procedure for gathering information on a sample of observations which are chosen from the population of interest utilizing a likelihood based example plan. In sample surveys, certain strategies are frequently used to enhance the accuracy and control the expenses of study information accumulation. These strategies acquaint an intricacy with the investigation, which must be represented with the end goal to create fair-minded appraisals and their related dimensions of accuracy. This section gives a concise introduction to the effect these structure complexities have on the testing change and condenses the qualities and accessibility of programming to do examination on sample introduction data.