In mathematics, var(3) typically refers to the variance of a data set containing a single value, which in this case is the number 3.

Variance measures how much the values in a data set differ from the mean (average). For a single value like 3, the variance is always 0 because there is no variability—every value is exactly the same as the mean.

Here's how it works:

• The mean of {3} is 3.
• The variance formula is:

$\text{Var}(x) = \frac{1}{n} \sum_{i=1}^{n} (x_i - \mu)^2$ Where:

• $x_i$ is each individual value,
• $\mu$ is the mean,
• $n$ is the number of values.

Since there's only one value (3), and it equals the mean, the variance is:

$\text{Var}(3) = 0$

Would you like more details or further explanations?

Here are 5 related questions to expand on this concept:

1. What is the difference between variance and standard deviation?
2. How do you calculate the variance for a set of multiple numbers?
3. What role does variance play in probability and statistics?
4. How does variance differ for population data and sample data?
5. Can variance ever be a negative value?

Tip: When dealing with a data set of one number, variance is always zero because there's no spread in the data!