To do this we'll convert our percentage into a decimal. Move the decimal 3 places to the left which will equal 0.125.
Now, we'll multiply all of our factors.
850 x .125 x 3 = 318.75
318.75 is the amount of interest they have earned in 3 years time.
Next, we will add that onto how much the original stock was worth which was $850.
850 + 318.75 = 1168.75
So, the stock will now be work $1168.80