That chart is based on data from the Labor Department’s American Time Use Surveys from 2003 to 2010. It shows that teenagers whose parents were immigrants spent an average of 26 minutes more per day on education-related activities than their counterparts with native-born parents.
That means that over the course of a week, children of immigrants spend about 27.7 hours in educational activities, whereas children of native-born Americans spend about 24.6 hours. (via Children of Immigrants Study More - NYTimes.com)