Solving Coefficient of Correlation

Hello to everyone on this forum! I am only new here as I stumbled across it while doing research for my Honours degree in Computer Science.

I am not the best at maths so I need some help with this equation. I'm sure you are familiar with the Coefficient of Correlation between two populations (not samples) X and y.

My problem is that, given all of X, and all of Y except Yn (the last value of Y) and their coefficient of correlation, solve for Yn.

If you need any more clarification, please say so and I will learn LaTex and post it.