Signal 3 out of three points on the same side of the mean f

Signal 3: ---?--- out of three points on the same side of the mean, fall beyond ---?---standard deviation above or below the center line.

Use words (all lowercase - except first letter at the beginning of the sentence) and not numerals. Note: more than one word may be required for each blank.

Solution

For an out of control signal- 3,

At least two out of three points on the same side of the mean, fall beyond two standard deviation above or below the center line.