What is the angle of elevation formed by the ramp and the ground?

  m ∡ x = 23° .

Using the mnemonic:   "SOH CAH TOA" .

Let's use "SOH" ;  that is:   "sin x = opposite/hypotenuse" ; since we have the values of "opposite" and "hypotenuse" (with respect to "angle x").

sin x = opposite / hypotenuse = (4.5) / (11.75) = 18/47 = 0.3829787234042553 ;

→  Solve for "x"  by taking the "arcsin" ("inverse sine") of each side (use calculator):

          →   arc sin x  =  arc sin (18/47)  =  22.518314130871 ; 

                     → Round to the nearest degree;  22.518 → rounds to:  23 .


                               →  m ∡ x = 23° .