True or false. valid statistical inference depends upon using randomization in the design for gathering data. a. true b. false
2. following the analysis of a well-designed, completely randomized experiment, it was reported that the observed effect was "statistically significant" which of the following statements best explains the meaning of the phrase "statistically significant"? a. the observed result made sense to the experimenter since it was what was hoped would happen. b. the observed effect happened because the experiment was properly designed and carried out without bias. c. the experimenter carefully employed the basic principles of experimental design in conducting the study. d. the laws of probability say that this observed result would be expected to happen by chance. e. the observed effect was sufficiently large so that it would rarely occur simply by chance.