Let's calculate the mean and median of the given numbers.

Given data (sorted):

820.43, 829.61, 859.10, 859.70, 864.64, 866.20, 867.63, 869.79, 871.98, 873.65,
875.04, 877.0, 877.07, 879.73, 879.81, 880.37, 880.93, 884.74, 886.25, 890.22, 900.68

1. Mean:

The mean is calculated as:

$\text{Mean} = \frac{\text{Sum of all values}}{\text{Total number of values}}$

Summing up all the values:

$820.43 + 829.61 + 859.10 + 859.70 + 864.64 + 866.20 + 867.63 + 869.79 + 871.98 + 873.65 + 875.04 + 877.00 + 877.07 + 879.73 + 879.81 + 880.37 + 880.93 + 884.74 + 886.25 + 890.22 + 900.68 = 18247.58$

Now, divide by the total number of values (21):

$\text{Mean} = \frac{18247.58}{21} \approx 869.88$

2. Median:

The median is the middle number when the values are arranged in order. Since there are 21 numbers, the median will be the 11th number in the list.

The 11th value in the sorted list is 875.04.

Final results:

• Mean: 869.88
• Median: 875.04

Do you want more details or have any questions?

Here are 5 related questions to consider:

1. How do outliers affect the mean and median?
2. What is the difference between arithmetic mean and geometric mean?
3. How would you calculate the mode of a dataset?
4. Can the median ever be larger than all the numbers in a set?
5. What if there were an even number of values—how would you calculate the median?

Tip: The median is less sensitive to extreme values (outliers) compared to the mean, making it a more robust measure of central tendency in skewed distributions.