Plot on a number line 8 2/5 away from 2 3/4

First, draw the number line and assign the values of the real numbers that correspond (See the figure attached).
  Now, let's represent the mixed numbers given in the problem.

 Let's start with 8 2/5: This mixed number is located between 8 and 9. The numerator 2 of the fractional part, tells us how far from 8 it will be located  and the denominator 5 indicates how many parts we must divide the space between these two numbers (8 and 9). 

 Now, to plot 2 3/4 on the number line, we have to follow the same proccedure: It is located between the numbers 2 and 3. The numerator 3 of the fractional part, tells us how far from 2 it will be located  and the denominator 4 indicates how many parts we must divide the space between 2 and 3.

C 10% Condition.

Step-by-step explanation:

Let's Look at them one by one.

A: Large Enough sample condition.

this is met because 600 students is a good number to carry out a surwey.

B: Randomization,  600 incoming freshman are definitely random.

C: we are left with C so the answer is C.