Error using * Incorrect dimensions

I am trying to do least squares fitting for a homework assignment

I have included my code and related workspace as an attachment. I am having issues with line 8. I have fiddled with the code but haven't found a solution.

(also I know I don't need the n variable its just there for now)

an explanation of what is wrong and how to solve would be very much appreciated. Thank you!

Answer 1

[Bjorn Gustavsson]

For problems like these you should learn to run the code line-by-line at the command-line prompt. Then check the size and type of the resulting variables, using size(X) and whos X for example. Also check which combinations of transposes makes your multiplications work and what shapes of the matrices are.

HTH