Answer:
 max 48, min 17
Step-by-step explanation:
Apparently, your plot is supposed to be ...
 1 | 77889
 2 | 011234456677788999
 3 | 01123445566678899
 4 | 58
The smallest stem is 1, and its smallest leaf is 7, representing a value of 17.
The largest stem is 4, and its largest leaf is 8, representing a value of 48.
The extremes represented by this plot are: max 48, min 17.