Presumably d meanst distance and t means time.
When t = 1, d = 2.5
When t = 3, d = 4
d = mt + b
2.5 = m + b [t = 1]
4.0 = 3m + b [t = 2]
1.5 = 2m [subtract]
m = .75 = slope
b = 1.75 = d-intercept
d = .75t + 1.75
d = 15/4 + 7/4 [t = 5]
d = 22/4 = 5.5 m from sensor
The solution would be x > 1 sorry if its wrong but hope it helps
