Match each sampling method described below AStratified B Sys

Match each sampling method described below:
(A)Stratified (B) Systematic (C) Simple random sample (D) Cluster

(a) To estimate the percentage of defects in a recent manufacturing batch, a quality-control manager at Intel selects every 8th chip that comes off the assembly line starting with the 3rd until she obtains a sample of 140 chips. Answer:

(b) To determine customer opinion of its boarding policy, Southwest Airlines randomly select 60 flights during a certain week and surveys all passengers on the flights. Answer:

(c) 24 Hour Fitness wants to administer a satisfaction survey to its current members. Using its
membership roster, the club randomly selects 40 club members and asks them about their level of satisfaction with club. Answer:

(d) A school official divides the student population into five classes: freshman, sophomore, junior, senior, and graduate student. The official takes a simple random sample from each class and asks the members’ opinions regrading student services. Answer:

Solution

a) To estimate the percentage of defects in a recent manufacturing batch, a quality-control manager at Intel selects every 8th chip that comes off the assembly line starting with the 3rd until she obtains a sample of 140 chips. Answer:STRATIFIED

(b) To determine customer opinion of its boarding policy, Southwest Airlines randomly select 60 flights during a certain week and surveys all passengers on the flights. Answer:CLUSTER

(c) 24 Hour Fitness wants to administer a satisfaction survey to its current members. Using its
membership roster, the club randomly selects 40 club members and asks them about their level of satisfaction with club. Answer:SIMPLE RANDOM SELECT

(d) A school official divides the student population into five classes: freshman, sophomore, junior, senior, and graduate student. The official takes a simple random sample from each class and asks the members’ opinions regrading student services. Answer:SYSTEMATIC