The average score on the first Physics test 64%, with a standard deviation of 14%. 15 students took the test. The average score on the second test was 70%, and 21 students took the test.

1. For the first test: What percentage of the students would you expect to have scored below 36%?
2. For the first test: What percentage of the students would you expect to have scored above 78%?
3. What is the weighted average score across both tests?