If the scores of 3 students in a test are 5, 6 and 7, find the standard deviation of their scores
Answer Details
To find the standard deviation of the scores, we need to first calculate the mean (average) of the scores:
mean = (5 + 6 + 7) / 3 = 6
Next, we calculate the deviation of each score from the mean:
deviation of 5 = 5 - 6 = -1
deviation of 6 = 6 - 6 = 0
deviation of 7 = 7 - 6 = 1
To calculate the standard deviation, we take the square root of the average of the squared deviations:
standard deviation = √[(1^2 + 0^2 + (-1)^2) / 3] = √(2/3) ≈ 0.82
Therefore, the answer is option (D), √(2/3).