Answer:
Yes, these cowboys certainly lived long lives, as evidenced by the high frequency of leaves for stems 7, 8, and 9 (i.e., 70-, 80-, and 90-year-olds).
Explanation:
The data distribution of longevity tend to lend credence to the quote because the cowboys from the write-up by Baron von Richthofen; Cattle Raising on the Plains of North America lived quite long lives. This is evident by the relatively high number or frequency of leaves for stem 7, 8, and 9. This implies they live till age 70 years, 80 years and 90 years.
