Answer:
The value of k=4
Explanation:
we have
f(x)=0.4x
This function represent a linear direct variation (The line passes through the origin)
we know that
If f(x) is shifting up by 4 units
then
The y-intercept of the function will be the point (0,4)
therefore
The function g(x) will be -----> g(x)=0.4x+4 (equation of the line into slope
intercept form)
The rule of the translation
f(x) --------> g(x)
(x,y) -------> (x,y+4)
The translation is 4 units up
therefore
The value of k=4