Answer:
17
Step-by-step explanation:
Do you even know what a stem-leaf plot is?
The scores lower than 80% are:
70, 70, 71, 78, 62, 62, 63, 68, 69, 69, 57, 57, 58, 49, 49, 30, and 21 percent according to the data given. That is 17 scores less than 80 percent.
