A psychologist is interested in knowing whether adults who were bullied as children differ from the general population in terms of their empathy for others. On a questionnaire designed to measure empathy, the mean score for the general population is 59.39. Random sampling of 51 scores obtained from individuals who were bullied yielded a mean of 54.72 and a standard deviation of 8.69. (Use these numbers only for this question!)

What is the z-value or t-value you obtained (your test statistic)?(numeric value only, including negative sign if required)