Suppose Harvard wants to know if fall semester students are satisfied with registration procedures. Of the 3540 students enrolled, surveys were sent to 325 students -- 100 randomly selected students taking only seat-based classes, 100 randomly selected students taking only online classes and 125 randomly selected studentstaking a blend of seated and online. Of the 325 students who received surveys, 70 returned the surveys. Select ALL the TRUE statements.

Select one or more:

a.The sampling method used is stratified random sampling.

b.The population size is 325.

c.The sample suffers from non-response since only 70 of 325 responded.

d.The sampling method use is convenience sampling.

e.The variable of interest is the classification of student

f.The population of interest is 3540 students.

g.The sample size is 325.