A paired-difference experiment10 dealing with response latencies for noise detection under two conditions used a sample of twelve 9-month-old children and reported a sample mean difference of 70.1 and standard deviation of 49.4 for the dif- ferences. In their discussion, the authors reported a statistic of 4.9 having P <0.01 for a two- sided alternative. Show how they constructed the r statistic, and confirm the P-value.