here is the code:

```
Bob = {"name": "bob", "assigbment": [48, 39, 98, 87],
"presentation": [78, 78, 89, 78], "lab_task": [67, 89, 89, 90]}
Jay = {"name": "bob", "assigbment": [48, 39, 98, 87],
"presentation": [78, 78, 89, 78], "lab_task": [67, 89, 89, 90]}
# print out info
print(Bob, Jay)
def average(marks):
total_sum = sum(marks)
total_sum = float(total_sum)
return total_sum / len(marks)
def get_average(student):
ass_avg = average(student["Assignment"])
pre_avg = average(student["presentation"])
lab_avg = average(student["lab_task"])
weight = ass_avg * 0.6 + pre_avg * 0.1 + lab_avg * 0.3
return weight
def letter_grade(weight):
if weight >= 90:
return ("HD")
elif weight >= 80:
return ("D")
elif weight >= 70:
return ("CR")
elif weight >= 60:
return "P"
else:
return ("f")
students = [Bob, Jay]
results = []
def class_average(students):
results.append(get_average(students[0]))
results.append(get_average(students[1]))
class_avg = average(results)
return class_avg
```