6 x 1 = 6 /2 =3. For 6*1/2
3/5 x 1/4 = 3*1/5*4 = 3/20
The sample of the population is 100 students since they acquired answers from students from middle school and high school, having 50 students each school. 50 + 50 = 100 students as the sample. The total population for either or both of the schools is/are undetermined.
In interval notation the domain would be: (-infinity,-2]U[2,3)U(3,+infinity)
