Understand the definition of the Arithmetic Mean.

The arithmetic mean, denoted as $\bar{x}$ (read as "x bar"), is a measure of central tendency. It is calculated by summing all the values in a dataset and then dividing by the total number of values in that dataset.

The formula for the sample mean is given by:

where:

• $\sum_{i=1}^{n} x_i$ represents the sum of all individual data values.
• $n$ represents the total number of data values in the sample.

The example provides a sample of birth weights (in grams) and states that there are $n=20$ values. Although not all 20 values are fully visible in the image, the sum of these values is given as $\sum x_i = 63338$ grams.

Substitute these values into the formula:

The sample mean of the birth weights is $\text{3166.9 g}$.