Answer:
Median
Order the data values from smallest to largest:
55, 57, 57, 57, 58, 58, 58, 59, 59, 60, 61, 61, 61, 62, 62, 62, 63, 63, 64, 64, 65, 65, 66, 67
As there is an even number of values, the median is the mean of the middle two values ⇒ Median = 61
Quartiles
55, 57, 57, 57, 58, 58, 58, 59, 59, 60, 61, 61 || 61, 62, 62, 62, 63, 63, 64, 64, 65, 65, 66, 67
The first quartile is the median of the data points to the left of the median ⇒ first quartile = 58
The third quartile is the median of the data points to the right of the median ⇒ first quartile = 63.5
Five-number summary
- Minimum: 55
- First quartile Q1: 58
- Median Q2: 61
- Third quartile Q3: 63.5
- Maximum: 67
Draw a box from the first quartile (58) to the third quartile (63.5)
Add the median (61) as a the vertical line through the box.
The whiskers are horizontal lines from each quartile to the minimum (55) and maximum values (67).