IQ test, are they really?

I found a this thread http://www.mathhelpforum.com/math-he...g-algebra.html when i was looking for the explanation to one of the test in the "The Ultimate IQ Test Book" pdf. The explanation was accurate, so you don't have to go and check,..... but then i found the following question in the test, which i could not find the explanation to anywhere.

Firstly I tried the 6 {7\COOSE8} to display fracs, but no joy, so sorry.

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#22

6 7/8, 2 9/16, 5 5/8, 3 3/16, 4 3/8, ?

What number should replace the question mark?

in the results part it states

#22

5 1/16: There are two alternate sequences: -1 1/4 and +1 1/4

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I am not sure if i got the alternating sequence right?

If the first sequence starts with 6 7/8 minus 1 1/4 then the 3rd and 5th numbers correct, but then the alternate sequence starts with second number 2 9/16 and it should follow into 4 number (does not) and then into the question mark number,

Is it only me or is there a mistake? should the 3 3/16 be 3 13/16 and then the 4th number and the 6 number will agree?

Can anyone help to logically arrive at the correct result with the numbers they have given?

I have checked and rechecked those numbers. and can send a scan?

Cheers