Hey there! :D
So I want you to think of a function as an input and output, where f(x)= y and x=x.
(x,y)
(0.4, 0.2)
So when 0.4 is equal to x, y is equal to 0.2.
So, you can plug in the point you do know.
(1.6, y)
Divide x by 0.4.
1.6/0.4= 4
0.2*4= 0.8
f(x)= .8
I don't know if you added another 0 to the decimal, but the function is set up so that f(x) is half of x. 1.6/2=.8 That is the answer.
I hope this helps!
~kaikers