Valium (diazepam) is a widely prescribed antidepressant and sedative. A study investigated how Valium works by comparing its effect of diazepam on sleep in seven knock-in mice, in which the a2 GABA A receptor is insensitive to Valium, and in eight wild-type control mice. The study found that Valium reduced sleep latency in both groups with no significant difference between the groups. According to the study authors, this lack of significance "is related to the large inter-individual variability that is also reflected in the low power (20%) of the test."(a) Select the best explanation as to why tests having low power often fail to give evidence against a null hypothesis even when the null hypothesis is really false. Because we have probably insisted on a significance level that is too small. Because a low-power test is more likely to give Type I errors. Because in order to detect an alternative which is close to the null hypothesis we need a high power test. Because if the difference between the null and the alternative hypotheses is large, it is more difficult to detect it.(b) Which aspects of this experiment most likely contributed to a low test power? Sort the answer options into the two boxes labeled "True" and "False". True False Answer Bank large effect size to be detected large variability in the population non random samples random sampling errors small variability in the population small sample sizes small effect size to be detected small significance level