Because more questions about statistics have been added to the state exam, a school district decided to add a probability-statistics unit to their ninth-grade general mathematics course. to determine whether the unit will have an impact on scores on the state exam, all ninth-grade students enrolled in a general mathematics course in the largest high school in the school district were randomly allocated into two groups. one group of 281 students received instruction in a new probability and statistics unit in addition to the traditional instruction; the other group of 311 students received only traditional instruction. students in both groups were given the state exam at the end of ninth grade to determine whether the group receiving additional instruction in probability and statistics had a higher average score than the group receiving just traditional instruction. what is the population in this study? (a)all students in ninth grade in the state. (b)the scores of all the students in the state. (c)all students in the traditional unit. (d)all students in the new probability-statistics unit. (e)all students in the ninth-grade general mathematics course in this school district.