Two Means - Matched Pairs (Dependent Samples): Videos & Practice Problems

Researchers recorded the difference in time (novel−familiar) that $20$ eight-month-old infants watched a puppet perform a surprising action. The sample mean difference was $\bar{x}=0.85$ seconds and the sample standard deviation was $s=1.10$ seconds. Test whether the mean difference is nonzero using a two-tailed $t$-test at the $\alpha =0.05$ level.