I have attached a picture of the dot plot that you described. Each dot on the number line represents one answer. So, the number of dots above the number 4 tells us that there were 6 students who have 4 email accounts.
The answer is that <span>There are exactly 6 students with 4 email accounts.</span>
The answer is that <span>There are exactly 6 students with 4 email accounts.</span>