Question

In a normal curve, roughly what percent of all cases fall within plus or minus two standard deviations

Answer 1

Answer:

We know that the total area under the normal curve is 100%. According to the empirical rule of Normal distribution:

Approximately, 68% of data lies within $\pm1$ standard deviations of mean.

Approximately, 95% of data lies within $\pm2$ standard deviations of mean.

Approximately, 99.7% of data lies with $\pm3$ standard deviations of mean,

Therefore, in a normal curve, roughly 95% of all cases fall within plus or minus two standard deviations.