The point F lies on 4.5 in the number line.
Number line is a One dimensional representation of point referring by a number only.
We know that if a point divides a line joining the points at x,y in the number line respectively in m:n ratio then that point lies on = (my+nx)/(m+n) in the number line.
Here in the give problem that,
Point D lies on -6 in number line
Point E lies on 8 in number line
And F lies between D and E points and DE:EF = 3:1
So the point F clearly divides the staright line DE joining the point D at -6 and E at 8 in 3:1 ratio.
So the point F lies on = (1*(-6)+3*8)/(3+1) = (-6+24)/4 = 18/4 = 4.5
Hence the point F lies on 4.5 in the number line.
Learn more about Number Line here -
brainly.com/question/4727909
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