Independent variables are also known as variables. O a. criterion O b. prophet O c. predictor O d. response QUESTION 2 A researcher wishes to have a sample with the same distribution as the population on a key variable. The best sampling method to use would be O a. stratified sampling Ob. systematic sampling O c. cluster sampling O d. a convenience sample QUESTION 3 The summation operation is represented by the symbol. O a, u Ob.s O c.a Od. E QUESTION 4 A variable is a(n) O a. individual selected to be included in a sample O b. measurable attribute that varies across individuals or changes over time O c. individual score