This is a double blind experiment because the patients were divided into the two treatment groups randomly.
It is not possible for this experiment to be single-blind or double-blind, because human subjects are involved.
This is only a single-blind experiment because the experimenters did not include a control group that received neither medication nor a blindfold and soft music.
This is only a single-blind experiment because patients will know which treatment they are receiving, although the examining doctor might not.
This is a double-blind experiment because the experimenters could prevent both groups of patients from knowing what sort of treatment the other group is receiving.
The number of heads in three tosses of a coin.
The number of rainy days in a given week.
The number of girls in a randomly selected family of five children.
The number of students over five feet tall at a randomly selected middle school.
The number of defective computer parts randomly selected from an assembly line.
The mean of X + Y is 6.2.
The standard deviation of X + Y is 0.7.
The variance of X + Y is 0.7.
The standard deviation of X - Y = 0.1
The standard deviation of X - Y = 0.5