Find the mean and variance for each of the data in Exercise.
First 10 multiples of 3
The 10 multiples of 3 are:
3, 6, 9, 12, 15, 18, 21, 24, 27, 30
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 = (1/10) × 742.5 = 74.25
Ans. Mean = 16.5 and Variance = 74.25
3