For the first question, we going to need the total number of students in 12th grade which is 20.
Then we going to localize into the 12th-grade table the columns known best for each language and sum it.
Answer: Now we identify that the language with more 12th students know best is Python.
For the second question, we sum the row they were taught a programming language at
school of 12th table.
Now using the total of 12th-grade students (20) and the last answer in decimal form we do the next:
We get the answer: 12 students were taught a programming language at school.
For the third question, we use the total number of 8th-grade students (25) and localize into the 12th-grade table the intersection of they knew Python the best and were not taught a programming language at school.
we divide this number (1) by the total 8th-grade students (25).
And multiply by 100 to get the percentage
Answer: 4%
The answer to the last question is: The difficulty to decide using the tables information is the form that the data is shown. One in number and the other in percentage. We need both in percentage in order to make the comparison.