The number of years since Lena graduated
from middle school can be represented by the
equation y = a - 12, where y is the
number of years and a is her age. Is the
relationship between the number of years
since Lena graduated and her age
proportional or nonproportional?

Answer these questions showing your work plz

1. there are 25 students who started computer programming in elementary school and 25 students who started computer programming in middle school. the first group had a mean final project grade of 95% and the second group had a mean final project grade of 92%. the line plot shows the differences after 10 rerandomizations. determine whether the difference in the means of the two groups is significant based on the line plot. explain your answer.

Suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12 y=7 when x=3