Hi, I think there is a small mistake in the exercise. If you check the 2 complaints row, the number of observations is 4, and the (x-Mean) 2 is 0.21. Then the f(x-Mean) 2 = 0.85, not 0.17, and the sum (x-Mean) 2 should be 9.23, not 8.54. Finally, the variance should be 0.71, not 0.66. The difference is very small but considering how strict seem to be the tests this would lead to a mistaken answer.
Correct me, please, if I am wrong.
F
Fabio·
Yes, it is wrong, it is 0,85 is the correct input. However, as it is an exercise to practice and understand the concept of Variance/std deviation, it does not really matter to be honest in my opinion.
Correct me, please, if I am wrong.