Question

1. Which of the following is not a paired data example?

   	A.	An insurance company is concerned that garage A is charging too much for repairing damage to cars. Ten damaged cars were taken to both garage A and another garage for estimates.
   	B.	We randomly select 20 couples and compare the time each individual spends watching TV
   	C.	A hypothesis of ongoing clinical interest is that vitamin C prevents the common cold. In a study involving 20 volunteers, 10 are randomly assigned to receive vitamin C capsules and 10 are randomly assigned to receive placebo capsules.
   	D.	In a warehouse, the employees have asked management to play music to relieve the boredom of the job. The manager wants to know whether efficiency is affected by the change. Efficiency ratings of 15 employees are recorded before and after the music system was installed.

Answer 1

Paired data means the observation has been taken from same set of samples two times.

So C is not a paired data example.