This is a statistic question.  A class of 70 students takes a test. 
Out of a possible 100 points, the mean = 66, max = 96 and min = 16. 
One particular student scores 84 points.

How likely is it for 30% of the class (or 21 students) to score higher
than 84 points?  (assuming that the outcome is governed by a known
type of distribution)

What type of distribution would it have to be?  Poisson, log normal, others?

For a log normal distribution, what would be the probability of an
event between 84 and 96?

For a poisson distribution, what would be the probability of an event
between 84 and 96?