Question 47
Measures of DispersionThe mean of the numbers 3, 6, 4, x and 7 is 5. Find the standard deviation.
- A.√2
- B.√3
- C.2
- D.3
Show the answer and explanation
Answer: A (√2)
Explanation
3 + 6 + 4 + x + 7 = 25, so x = 5. Squared deviations are 4, 1, 1, 0, 4, total 10; variance = 10/5 = 2, so SD = √2.