Question:
Find the mean and variance for the first 10 multiples of 3
Solution:
The first 10 multiples of 3 are
3, 6, 9, 12, 15, 18, 21, 24, 27, 30
Here, number of observations, n = 10
Mean, $\bar{x}=\frac{\sum_{i=1}^{10} x_{i}}{10}=\frac{165}{10}=16.5$
The following table is obtained.
Variance $\left(\sigma^{2}\right)=\frac{1}{n} \sum_{i=1}^{10}\left(x_{i}-\bar{x}\right)^{2}=\frac{1}{10} \times 742.5=74.25$
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