Answer:
1
Step-by-step explanation:
The slope of the perpendicular is the negative inverse of the slope of the line.
m = -1 / (-⅓)
m = 3
The slope between the two points is 3, so:
3 = (15 − 6) / (4 − n)
3 (4 − n) = 9
4 − n = 3
n = 1
