Answer
a) Mean:0, standard deviation:1.
b) The standardized z-scores have no units.
Work Step by Step
a) Standardized z-scores have a standard normal distribution, hence the mean is 0 and the standard deviation is 1.
b) The standardized z-scores have no units (because to determine them you divide a value in beats per minute by a value in beats per minute, these cancel each other out).
