Respuesta :

Answer: 35

Step-by-step explanation:

     The average can be found by adding their ages together and dividing by the number of ages.

     Given:

[tex]\frac{19+20+20+21+x}{5}[/tex] = 23

     Multiply both sides of the equation by 5:

19 + 20 + 20 + 21 + x = 115

     Combine like terms:

80 + x = 115

     Subtract 80 from both sides of the equation:

x = 35

                    Erica is 35.