If a Particular Batch of Data Is Approximately Normally Distributed

Multiple Choice

If a particular batch of data is approximately normally distributed, we would find that approximately

A) 4 of every 5 observations would fall between ±1.28 standard deviations around the mean.
B) 2 of every 3 observations would fall between ±1 standard deviation around the mean.
C) 19 of every 20 observations would fall between ±2 standard deviations around the mean.
D) all of the above