5.A student organization wants to assess the attitudes of students towards a proposed change in the hours that the undergraduate library is open. They randomly select 100 freshman, 100 sopho- mores, 100 juniors, and 100 seniors.

What type of sampling design was used in this study?_______

A. Multistage Sample

B. Stratified Random Sample

C. Simple Random Sample

D. Cluster Sample

E. Systematic Random Sample

7.For each set of variables listed, identify which variable should be the response variable and which should be the explanatory variable

Variable1: The amount of money earned for a part-time job

Variable2: The number of hours worked_______

A. V1: response variable, V2: explanatory variable

B. V1: explanatory variable, V2: response variable

V1: The weight of a package V2: The first-class postage rate at the post office_______

A. V1: explanatory variable, V2: response variable

B. V1: response variable, V2: explanatory variable

V1: The salary of a high school teacher V2: The number of years of teaching experience_______

A. V1: explanatory variable, V2: response variable

Find the mode of the above data. Mode =____________