Answer:
3
Step by Step:
Subtract the tip ($6) from the total ($39)
11x=33
Then divide 33 by 11, leaving you with the value of x.
x=3
The lesson was 3 hours long.
Answer:

Refer to the attachment for explication of steps. :)
Answer:
im not sure how the data should be interpreted but here is the distribution. It goes up by .416
Step-by-step explanation:
the average of the first 8 games is 24
the average of the 12 games is 24.416