A group of students wants to determine the effect of family income on the study behavior of students at CLSU. Dueto time and budget constraints, they plan to interview a sample of CLSU students. Suppose a random sample of nine sections was selected from the list of all CLSU sections and all students from these sections were interviewed. The sampling method used is sampling. 0 stratified random 0 systematic 0 simple random 0 cluster Descriptive statistics are methods for using sample data to make general conclusions about populations. In drawing a sample of telephone numbers in a specied area, every 1 [10th number is selected from the telephone directory used as a sampling frame. The sampling procedure described is called systematic sampling. A survey is to be conducted to determine the level of satisfaction of the customers. The list of all 99 customers was obtain ed and a rand om sample of 30 will be selected. If stratified sampling with proportional allocation will be used having the following as strata: age 20 and below (21), age 21-30 (32], age 30-40 (33), and age 40 and above (13). The number of customers age 20 and below to be selected is Note: the varues enclosed by parenthesis are the population size per strata