MediumMath and Logic
Standard deviation of {1, 2, 3, 4, 5}?
Riddle
Standard deviation of {1, 2, 3, 4, 5}?
Choose an answer
A.1.0
B.2.0
C.2.5
D.1.414 (2?)
Hint: It's a word with 0 letters, starting with "1".
Answer
1.414 (2?)
Why this is the answer
The mean is 3. Squares of deviations: (1-3)^2=4, (2-3)^2=1, (3-3)^2=0, (4-3)^2=1, (5-3)^2=4. Average is 10/5 = 2. SD is sqrt(2) ? 1.414.
This riddle is filed under Math Riddles and rated Medium.