While babysitting your 18 month oldniece, you notice her vocabulary has seemingly doubled. This is a phenomenon known as the "Naming Explosion". However, in your latest development psychology class, your Professor said that the naming explosion does not occur until around 13 months. You ask parents when they remember the 'naming explosion' happening for their child(ren). With already knowing how to calculated descriptive statistics for your sample, you find

18.6 = sample mean

6.2 = variance

36 = sample size

Calculate the t- test statistic used to determine if your sample is typical.