Koizumi took 6 math tests last semester, the average score of the last 4 tests was 4.8 points higher than the average score of the 6 tests, and the average score of the first, second and sixth tests was 3.2 lower than the average score of the 6 tests Points, the average score of the first 5 times is lower than the average score of the 6 times.
小泉上学期进行了6次数学测验，后4次的平均分比6次的平均分提高了4.8分，第一、二次和第六次这三次的平均分比6次的平均分低了3.2分，前5次的平均分比6次的平均分降低了多少分．
<result>1.92</result>