The lower quartile has a percentile rank of _______.

The following statistics on the family income in pesos are given below:
 $P_{25}=4\ 500$  
 $P_{50}=\ 7\ 500$  
 $P_{75}=10\ 800$  
 $P_{80}=12\ 700$  
What percent of the families earn less than or equal to 4,500 pesos?

What is the percentile rank of 16 in the statement:

“15% of the students in the class are above 16 years of age.”