Assessment 1. A farmer has four orchards of apple trees which are located at dif
ID: 2922641 • Letter: A
Question
Assessment 1. A farmer has four orchards of apple trees which are located at different locations on his farm. Each orchard has 200 apple trees. He wishes to find out whether the apple trees are infested with a certain type of insect. If this is so, he would hire a crew to spray his trees. Instead of examining all 800 trees he decides to select a sample of trees and just examine these. There are three proposed sampling plans described below: Plan 1: Randomly select 100 trees from the 800 trees. Plan 2: Randomly select 20 trees from each of the 4 orchards. Plan 3: Randomly select 1 orchard from the 4 orchards, and then select all trees from the selected orchard. For each of the above plans, identify the type of sampling method being proposed (simple random sample, stratified random sample, cluster sample, systematic sample). Plan 1: Plan 2: Plan 3: rst class passengers scheduled on a flight. In addition to the usual security 2. There are 16 fi screening, 4 of the passengers will be subjected to a more complete search. Here is the first class passenger list, denoted by which Section that the passenger is seated in. Section 1 1. Bergman 2. Cox 3. Fontana 4. Perl Section 2 5. DeLara 6. Forrester 7. Rabkin 8. Burkhauser Section 3 9. Frongillo 10. Roufaiel 11. Castillo 12. Dugan Section 4 13. Swafford 14. Clancy 15. Febo 16. LePage (a) Select a simple random sample of 4 passengers. (b) Select a cluster sample of 4 passengers. Use the Sections of passengers as clusters (e) Select a 1-in-4 systematic sample of 4 passengers.Explanation / Answer
1) Simple random sampling: selecting people from each group without bias.
Stratified sampling: Selecting a random sample of people from each partitioned group.
Cluster sampling: Selecting group of groups and selecting random samples from a group
Systematic sampling: Sampling the data with interval range. Example: sampling from a group of 1 to 20 with interval 4 as 1,5,9,13,17
Plan A: Simple random sample. Because selecting 200 from a total of 800 trees without bias.
Plan B: Stratified Sampling, Becuase selecting a random sample from each group.
Plan C: Cluster sample, Because selecting of a group from groups and sampling the trees.
2) N=16 , Sub groups= 4 with 4 samples on each group:
a) Simple random sample of 4: 4/16
Example: 1,2,3,4 or 2,5,8,10 or 5,8,10,16 or 1,6,8,16 etc...can be any
b) A cluster sample of 4 passengers:
Select any group Example: Selection 3 and passengers 9,10,11, and 12.
c) select 1 in 4 systematic sample of 4 passengers: selection will be each group but with a fixed interval.
Select group example: 1,5,9,13 or 2, 6, 10, 14 etc..