What the ratio tells us is that for every 2 inches that fall in January, 5 are predicted to fall for the entire winter.
For this problem we can cross multiply (if you haven't done this yet, just let me know and i can edit this answer to do the problem a different way)
We set the equation up to compare the two ratios with X representing the predicted total snowfall
Now, we multiply the value on the top of the first fraction by the value on the bottom of the second fraction and vice versa
2X=5*34
Now, we can simplify
2X=170
Now, we can divide by 2 on both sides in order to get X alone
X=85
So, the predicted snowfall for the winter is 85 inches