Answer:
The range of the data is 75 - 21 = 54 (the difference between the two "whiskers"
The median of the data is 50 (middle line inside the box)
The first quartile "Q1" is 34 (left edge of the box). This means that 25% of the values are < 34.
The third quartile "Q3" is 69 (right edge of the box). This means that 25% of the values are > 69.
The interquartile range is 69-34 = 35. (subtracting Q3 - Q1) 50% of the data falls in this range, from 34 -69. 50% of the data falls in the box.
Let me know if you have questions about this answer. I'm happy to help.