A random survey of 25 students in each grade level of a school was conducted to determine whether the students preferred to have less time between classes. The results are shown in the table.

There are 275 students in each grade. Based on the survey results, which statement is the best prediction about all
the students in these grade levels?

C. 

Firstly, we know that the slopes are the same because parallel lines have the same slope. Then we can find the y-intercept by using the slope and point in slope intercept form. 

y = mx + b ---> plug in known values
3 = (3/2)(2) + b ---> Multiply
3 = 3 + b ---> Subtract 3 from both sides. 
0 = b

Since the intercept is 0, you will not see a number after the slope and x.