Moderate -0.3 This is a straightforward one-sample z-test with all values provided explicitly. Students must identify it as a one-tailed test, calculate the test statistic using the given mean, population SD, and sample size, then compare to the critical value. While it requires correct application of hypothesis testing procedure, it involves no conceptual challenges or multi-step problem-solving beyond standard textbook methodology.
80 randomly chosen people are asked to estimate a time interval of 60 seconds without using a watch or clock. The mean of the 80 estimates is 58.9 seconds. Previous evidence shows that the population standard deviation of such estimates is 5.0 seconds. Test, at the 5% significance level, whether there is evidence that people tend to underestimate the time interval. [7]
80 randomly chosen people are asked to estimate a time interval of 60 seconds without using a watch or clock. The mean of the 80 estimates is 58.9 seconds. Previous evidence shows that the population standard deviation of such estimates is 5.0 seconds. Test, at the 5% significance level, whether there is evidence that people tend to underestimate the time interval. [7]
\hfill \mbox{\textit{OCR S2 2010 Q4 [7]}}