Help with if loop with array

[ptc-3679927]

There's no error in the worksheet, but the answer is incorrect. How do i define in Mathcad so that it would read each scalar in the array instead of a whole. 

(Mathcad 15)

[LucMeekes]

Yes, no error message from mathcad. ..
And the answers are all correct...given the equations and formula.
BUT: what did you expect to get. What is your purpose?
Please explain.

Success!
Luc

[AlanStevens · Accepted solution]

One way is as follows:

[Werner_E]

Turning the calculation into a function and calling that function vectorized might be an option.
Furthermore you have to use the logical "or" operator to connect your two conditions.

You don't have to name the formal function  argument "class_id" as I did, you may name it simply "class" as well.

Furthermore you may consider making "Dp" a second function argument.

MC15 worksheet attached