Statistics: Sampling Techniques Practical Exam Questions And Answers/2024.

Random samples - correct answer are selected by using chance methods or random numbers. ex random samples - correct answer Number each object in the population; Place the numbered card in a box and mix them; Select as many card as needed to form the sample. Systematic samples - correct answer Numbering each object in the population; Selecting every Kth value. ex Systematic samples - correct answer suppose there are 2000 students in an elementary school and a sample of 50 students is needed. Solution: give a number to each student. then find k=2000/50=40 and every 40th student would be selected. Choose randomly the 1st student from 1 through 40. Stratified samples - correct answer are selected by Divide the population into groups (X { typically: race, age, gender, religion, education}) Obtain a random or systematic sample of each X; Put together the samples obtained in the previous step for your ________. ex stratified samples - correct answer There are 500 students in a private school in which 350 are male and 150 are female. We need 11 students from each. Solution males k=350/11=31.81 approximately 31 round down. Then randomly choose 1 from 31. then count from that number 31 times till you get 11 students. same goes for females. Cluster samples - correct answer are selected by Divide the population into sections "often geographical"; Obtain a random or systematic sample of each; Put together the samples obtained in the previous step for your ________. ex cluster samples - correct answer assume town A has 500 families. In this town there are 20% low income families, 50% middle income families, and 30% upper-income families. We need 30 families from each cluster. Solution .20(500)=100 low income .5(500)=250 middle income .3(500)=150 upper income. sample - correct answer part of a population Random, systematic, stratified, cluster - correct answer Name and define the four basic sampling methods. stratisfied - correct answer Classify each sample as random, systematic, stratified, or cluster. Mail carriers of a large city are divided into four groups according to gender male or female and according to whether they walk or ride on their routes. Then 10 are selected from each group and interviewed to determine whether they have been bitten by a dog in the last year. (1-3) cluster - correct answer Classify each sample as random, systematic, stratified, or cluster. In a large school district, all teachers from two buildings are interviewed to determine whether they believe the students have less homework to do now than in previous years. systematic - correct answer Classify each sample as random, systematic, stratified, or cluster. Every seventh customer entering a shopping mall is asked to select her or his favorite store. random - correct answer Classify each sample as random, systematic, stratified, or cluster. Nursing supervisors are selected using random numbers to determine annual salaries. systematic - correct answer Classify each sample as random, systematic, stratified, or cluster. Every 100th hamburger manufactured is checked to determine its fat content. Random Sampling - correct answer Selection using chance method or random numbers. Equal chance. Systematic Sampling - correct answer Selection is completed by putting the population in order and then selecting every XTH element in the population. (5th, 100th, etc) Stratified Sampling - correct answer Completed by dividing the population into at least two different subpopulations. They share the same characteristics, then a sample is drawn from each. (split by gender + sample, etc.) Cluster Sampling - correct answer Completed by first dividing the pop. area into sections or groups, then randomly selecting a few of those sections + choosing all members from those selected sections. Convinience Sampling - correct answer Uses results that are readily and easily available Census - correct answer ask everyone Convenience - correct answer Ask everyone you see