I have a dictionary of student grades. I want you to use Python to place every single grade into a list and then calculate the average grade from that list. Here is the dictionary:

`student_grades = {"Phil":[81, 73, 91], "Bill":[89, 64, 84], "Lillian":[83, 81, 86], "Jack":[94, 93, 92], "Jill":[73, 20, 38], "Jorge":[64, 70, 95]}`
Sure thing. Here is the code that places each grade into a new list called `all_grades` and then calculates the average from that list.

```Python
student_grades = {"Phil":[81, 73, 91], "Bill":[89, 64, 84], "Lillian":[83, 81, 86], "Jack":[94, 93, 92], "Jill":[73, 20, 38], "Jorge":[64, 70, 95]}
all_grades = []

# Loop through the values of the student_grades dictionary
for grades in student_grades.values():
  all_grades.extend(grades)

# Calculate the average grade
avg_grade = sum(all_grades) / len(all_grades)

# Print avg_grade
print(avg_grade)
# Output: 76.16666666666667
```

Let's break down the code. We create an empty list called all_grades. We then use a for loop that iterates through the dictionary values by using the `student_grades.values()` method. Inside the loop, we use the `extend()` method to add each grade to the all_grades list. Note that you can also use a nested for loop, but this way reduces the amount of code. Next, we calculate the average by dividing the sum of the all_grades list by its length. Lastly, we print out the average grade. 

If you have any other questions, please let me know.