7. 要求用户输入班级人数，之后依次输入每位学生的成绩，最后打印该班级总成绩和平均成绩

为了实现这个功能，你可以采用编程语言如Python编写一段简单的程序。这里我将以Python为例来解释：

class Student:
    def __init__(self):
        self.score = []

def input_scores():
    class_size = int(input("请输入班级人数："))
    total_score = 0
    for i in range(class_size):
        score = float(input(f"请输入第{i+1}位同学的成绩："))
        total_score += score
        student = Student()
        student.score.append(score)
    return total_score, student.score

total_score, scores = input_scores()
average_score = total_score / len(scores)

print(f"班级总成绩：{total_score}")
print(f"班级平均成绩：{average_score}")

# 如果需要，还可以计算最高分和最低分等
highest_score = max(scores)
lowest_score = min(scores)
print(f"最高分：{highest_score}")
print(f"最低分：{lowest_score}")