10.3#7

It is saying that the scalar projection is incorrect, while it is also saying that the vector projection is correct. I do not understand why it is saying this or why it is even happening?

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Well....in this case the reason it's happening is because you computed the scalar projection incorrectly.

You've correctly computed that the vector projection of b on a is [(a.b)/(a.a)] a=[-11/38]a. But then you tried to use [(a.b)/(a.a)] for the scalar projection, which only works if a is a unit vector. You could get this by replacing a by the unit vector a^ = a/|a| = a/√38; since |a^|=1 this is the same thing as saying that the scalar projection is a^.b which I think is the way we talked about it in class, or what is the same thing as a.b/√38. which is the way the textbook talks about it in the subsection of 10.3 that talks about projections. 

(ps y'all: yah gotta read the textbook. Really you do.)