Trying to make a goal seek like program using fsolve?

this is the code I currently have

clear all; close all; clc
f= @(x)  Average1(x)-65;
engineering= 30; % Intiall estimate 
function Average = Average1(engineering) % final grade 

engineering = fsolve0(f,engineering)
calculus= 55;
chemistry= 76;
physics= 85;
english= 50;

a= calculus+chemistry+physics+english+engineering;
Average = a/5;

 
end

when I try to run it i don't get any errors or outputs.

I am trying to make a program that will take 4 veriable values and a wanted avereage of 65 to find the 5th veriable (in this case engineering) minimum value to get a overall average of 65. I am unsure of what am doing wrong I know that the answer for Engineering should be 59 to get a average of 65.

Answer 1

[Torsten]

clear all; close all; clc
f= @(x)  Average1(x)-65;
engineering= 30; % Intiall estimate 
engineering = fsolve(f,engineering)

Equation solved.

fsolve completed because the vector of function values is near zero
as measured by the value of the function tolerance, and
the problem appears regular as measured by the gradient.

engineering = 59.0000

f(engineering)

ans = 1.2486e-08

function Average = Average1(engineering)
  calculus= 55;
  chemistry= 76;
  physics= 85;
  english= 50;
  a= calculus+chemistry+physics+english+engineering;
  Average = a/5;
end

[Walter Roberson]

syms x
solve((55+76+85+50+x)/5 == 65)

ans = 

59