posted by Laly on .
Answer the following:
What does it mean to say that x = 152 has a standard score of +1.5?
What does it mean to say that a particular value of x has a z-score of -2.1?
In general, what is the standard score a measure of?
standard score = z
z = (x-mean of whole population)/sigma of whole population
In other words z measures how many standard deviations your data point x is away from the mean of the population.
z = 1.5 means your data point x is 1.5 standard deviations bigger than the average of the population
z = -2.1 means your data point is 2.1 standard deviations below the mean.