Reseachers questioned if there was a change in the personality trait of openness to experience for students who attend 4-year colleges. They measured openness to experience with a standard personality questionnaire for 28 students at the beginning of their freshmen year of college (Time 1) and then again at the end of their senior year of college (Time 2). The mean difference value (x2x1) was 1.16, with a standard deviation of 1.31. Calculate the t-statistic. Report your answer rounded to the nearest two decimal places