In an experiment, participants are usually assigned to treatments ...

[saraeharris]

In an experiment, participants are usually assigned to treatments using random assignment. The reason for using random assignment is ____.
 
  a. to allow the experimenter to manipulate participant variables
 b. to allow the experimenter to manipulate environmental variables
  c. to help control extraneous variables
 d. to increase the reliability of the outcome measures

Question 2

In sampling notation,  = n/N refers to ____.
 
  a. the number of cases in the sampling frame
  b. the number of cases in the sample
 c. the number of possible subsets
 d. the sampling fraction

[vseab]

Answer to Question 1

c

Answer to Question 2

d

[saraeharris]

Wow, this really help

[xiaomengxian]

Excellent