I am looking at an example problem in my textbook and its solution. Can someone look at this picture/ problem and its solution and tell me where they got the yield to maturity.

I am looking at an example problem in my textbook and its solution. Can someone look at this picture/ problem and its solution and tell me where they got the yield to maturity.

The yield maturity is the constant discount rate that makes the present value of the cash flows equal to the bond price.
Thus
$$114.49 = 100(1+y)^{-4} + 10\sum_{k=1}^{4} (1+y)^{-k} = 10\frac{(1+y)^{-1}[1-(1+y)^{-4}]}{1 - (1+y)^{-1}}+100(1+y)^{-4}\\=10\frac{1-(1+y)^{-4}}{y}+100(1+y)^{-4}$$
Solving numerically (using for example Newton's method) we find $y= 0.05834= 5.834\, \%.%$