Question

a sample of chess players (x1) and checker players (x2) were given an iq test. the results of the iq tests were analyzed with a t - test. the standardized difference (t) was 2.15. the critical value (tcv) was 2.05. the results are significant, so we reject the null hypothesis. the results are not significant, so we reject the null hypothesis. we cannot make a conclusion on results (t - tcv = 0.1) that are not significant. the results are not significant, so we fail to reject the null hypothesis. the results are significant, so we fail to reject the null hypothesis.

Explanation:

Step1: Compare t - value and critical value

In a t - test, if \(t>t_{cv}\) (where \(t\) is the calculated t - statistic and \(t_{cv}\) is the critical value), the results are significant. Here, \(t = 2.15\) and \(t_{cv}=2.05\), so \(2.15>2.05\).

Step2: Determine action regarding null hypothesis

When results are significant, we reject the null hypothesis.

Answer:

The results are significant, so we reject the null hypothesis.