It has been reported that half of americans show road rage. for this claim to have strong external validity, which of the following would have been the best sample for the researcher to have used?

When the communist, under mao, took control of china in 1949 they announced total support support for which country and its ideology?

What was governor faubus’s public stance on integration of central high school?

Pj conducts an experimental study on the effects of soft music during high stakes science testing. he randomly assigns students at the school. in one condition he does not provide music for testing while in the other group he does provide the music. he administers a pretest at the beginning of the year and a posttest at the end of the year. pj’s design is best described as a: a.static group comparisonb. pretest-posttest control group designc.control-group-time-series designd. nonrandomized control-group pretest-posttest design