I asked people how many times they visited their local pub in a 'normal' week.
The result can be zero, one, two, three, four, and five and more.
- The mean is 2 and the standard deviation is 1.3.
- So two standard deviations above the mean is 4.6.
- However, two standard deviation below the mean is -0.6.
Is this negative figure an error? How do I interpret it?