I wonder if there is anybody that can help me with my project . I did the first part of the question and I get the answer but the last part suddenly an error appears saying this value must be scalar or vector. I really don't get where I did wrong.
You define all of your values (beta, q, etc.) as single valued variable (AKA scalars) and it works to find z for one value. Then you define i as an index variable from 1 to 14. (Mathcad starts at 0 by default unless you change ORIGIN.)
Then you define I, HR, and SR as vectors (indexed by i) but when you try to index beta (or q) Mathcad finds scalars, so you get red in yiour equation and the calculation fails.
Note that z will equal 1 (the value you defined as the guess for your solve block, not the 0.769 you found. It will stay that way until you redefine it.
Need to spend more time reading "help," or "getting started."
In addition to what Fred point out, in one expression you have z(beta_i,q_i), so you are calling z as a function. You do not have it defined as a function though. Also, in another equation you have z multiplied by (beta_i,q_i). That does not mean anything to Mathcad. Is z supposed to be a function?