A population of middle school students contains 160 sixth graders, 180 seventh graders, and 140 eighth graders. Nine seventh graders were part of a random sample of the population chosen to participate in a survey. For the sample to accurately represent the population, about how many sixth graders should be chosen? A.7 B.8 C.14 D.16
DeWayne wants to find out what career his fellow middle school students would like to pursue. He plans to collect three samples. Which statements describe good methods for collecting the samples? Check all that apply. 1.Interview students at lunch because it is likely that students with different interests will be present. 2.Interview students in the art club because they are creative and will come up with fun answers. 3.Interview students in the robotics club because they are focused on academics and concerned about their future. 4.Interview students in English class because everyone has to take English, and he can reach a variety of students. 5.Interview students and provide only four choices so that the data does not get complicated.
Adriana, Henry, Malik, and Richard each design surveys to determine the most popular way seventh graders purchase music. Adriana samples the five friends sitting at her lunch table. Henry samples every boy in his homeroom class. Malik samples every student using an MP3 player while waiting for the bus. Richard samples the first student alphabetically on the class roster from each of 12 classes. Which sample is likely to produce the most valid results? A.Adriana’s sample B.Henry’s sample C.Malik’s sample D.Richard’s sample
3.A town hosts an Arbor Day celebration. Each of the 105 families attending gets to choose a sapling to take home as they leave. Michelle and Ari each design surveys in order to determine the average height of the saplings. Michelle samples the first 20 families leaving the celebration. Ari samples every fifth family leaving the celebration. Which best explains which student’s sample is likely to produce more valid results? A.Michelle’s because she sampled the saplings of every family in her group B. Michelle’s because she sampled the saplings of the first 20 families to choose their saplings C.Ari’s because she sampled saplings chosen at different times D.Ari’s because she sampled one more sapling than Michelle sampled