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Based on the same previous scenario, calculate the deviation (score - mean). Square each response and then add the deviation squared. Divide the answer by n. What is the variance?

6, 7, 7, 8, 8, 8, 8, 9, 9, 10.

User Vojto
by
8.5k points

1 Answer

1 vote

Explanation:

1. Calculate the mean of the data: (6 + 7 + 7 + 8 + 8 + 8 + 8 + 9 + 9 + 10) / 10 = 8

2. Subtract the mean from each data point to get the deviation:

  • 6 - 8 = -2
  • 7 - 8 = -1
  • 7 - 8 = -1
  • 8 - 8 = 0
  • 8 - 8 = 0
  • 8 - 8 = 0
  • 8 - 8 = 0
  • 9 - 8 = 1
  • 9 - 8 = 1
  • 10 - 8 = 2

3. Square each deviation:

  • -2^2 = 4
  • -1^2 = 1
  • -1^2 = 1
  • 0^2 = 0
  • 0^2 = 0
  • 0^2 = 0
  • 0^2 = 0
  • 1^2 = 1
  • 1^2 = 1
  • 2^2 = 4

4. Add up the squared deviations: 4 + 1 + 1 + 0 + 0 + 0 + 0 + 1 + 1 + 4 = 12

5.Divide the sum of squared deviations by the number of data points (n-1), which is 9 in this case: 12 / 9 = 1.33

Answer:
So, the variance is 1.33.

User Yasser Asmi
by
7.2k points