Дисперсия ряда 2,1,1,2,5

To calculate the variance of a data set, you can follow these steps:

1. Calculate the mean (average) of the data set.

   • For the data set 2, 1, 1, 2, 5, the mean is: (2 + 1 + 1 + 2 + 5) / 5 = 11 / 5 = 2.2

2. Subtract the mean from each data point and square the result.

   • (2 - 2.2)^2 = 0.04
   • (1 - 2.2)^2 = 1.44
   • (1 - 2.2)^2 = 1.44
   • (2 - 2.2)^2 = 0.04
   • (5 - 2.2)^2 = 7.84

3. Calculate the average of the squared differences. This is the variance.

   • (0.04 + 1.44 + 1.44 + 0.04 + 7.84) / 5 = 10.8 / 5 = 2.16

So, the variance of the data set 2, 1, 1, 2, 5 is 2.16.