A consumer group decides to test the effectiveness of a new "organic" laundry detergent. They intentionally get grass stains on a sample of 60 white T-shirts in order to see how well the detergent will clean them. Each shirt is randomly assigned to one of three water temperatures ( cold, warm or hot), and one of two wash cycles ( regular or delicate). The level of cleaning for each shirt is recorded on a scale from one to ten; the person evaluating the cleaning level is unaware of the treatment used on the shirt. The average cleaning level for each treatment group is calculated.
Identify the following for the experiment:
A. 1) Explanatory variables
2) Response variable
3) Number of treatments
4) The experiment units are:
B. The average cleaning level is a Parameter or Statistic ?
C. Is blinding used in the experiment? (Explain the reason for using blinding in a n experiment)