Find the mean and variance for each of the data in Exercise.
6, 7, 10, 12, 13, 4, 8, 12
We know that Mean, 
Where n = number of observations and 
= Sum of total observations
∴
From the given data, we can form the table:
We know that Variance, σ2 = 
∴ σ2 = (1/8) × 74 = 9.25
Ans. Mean = 9 and Variance = 9.25
2