Zadacha

students = [
    {
        "name": "Александра",
        "class": 10,
        "grades": [6.00, 5.50, 5.75]
    },
    {
        "name": "Борислав",
        "class": 11,
        "grades": [4.00, 5.25, 4.75]
    },
    {
        "name": "Гергана",
        "class": 10,
        "grades": [5.00, 6.00, 6.00]
    },
    {
        "name": "Даниел",
        "class": 12,
        "grades": [3.50, 4.00, 3.75]
    }
]

for student in students:
    sredna_ocenka = sum(student["grades"]) / len(student["grades"])
    print(student["name"], sredna_ocenka)