TEST YOURSELF 1. A researcher wants to know the average age of teachers in a certain school. All of the fifty teachers from the primary, intermediate, and accordary levels were interviewed for the purpoan. Listed below are the ages of the teachers. Ages of Teachers to a Public School 27 P 20 P 31 37 22 P I 32 35 58 1 27 13 I 42 37 P 28 F 42 50 I 33 43 1 40 P 28 32 28 P I 52 F 29 40 35 1 37 I 25 22 F 42 P 62 1 28 P 56 30 31 P 32 45 48 28 P 39 P 30 P 42 P 42 P 29 P Legend: P - Primary I - Intermediate S - Secondary What is the average age of all the teachers? Find the average age of a sample size of 15 using: simple random sampling b. systematic random sampling stratified random sampling