Author Question: Suppose you have a herd of 100 cows and you need to select a simple random sample of 5 cows to test ... (Read 120 times)

burton19126 · **on:** Jul 24, 2018

Suppose you have a herd of 100 cows and you need to select a simple random sample of 5 cows to test for a certain disease. You call the cows in for the evening, and pick the 5 that arrive first. Is this a simple random sample? Why or why not?

Question 2

Suppose you want to find out what percentage of students at your university would pay extra fees for the use of a new recreation center, and you want a simple random sample of 100 students. Suppose you go to the current recreation center and ask every 10th student who comes in the door to participate in your survey, until you have 100 people. Does this method of sampling give you a simple random sample? Explain your answer.

macybarnes · **Reply #1 on:** Jul 24, 2018

Answer to Question 1

NO. THERE IS BIAS TOWARDS ANIMALS THAT ARE POSSIBLY HEALTHIER, MORE AGILE, OR YOUNGER, ETC; NOT EVERY SUBSET OF 5 ANIMALS HAD AN EQUAL CHANCE OF BEING THE CHOSEN SAMPLE.

Answer to Question 2

NO. ONLY THOSE WHO ATTENDED THE REC CENTER THAT DAY WILL HAVE ANY CHANCE OF BEING INCLUDED IN THE SAMPLE.