A meteorologist reports that the ratio of snowfall in January to total snowfall during the average winter is 2 to 5. If 34 inches have falled in January of the current year, find the predicted total snowfall for the entire winter.

First write out the proportions/ratios, and use x for the unknown number.
2:5 = 34:x
Then, you find out how much more 34 is from 2, so divide 34 by 2. 
The answer will be 17, which means, the proportions is 17 times of everything.
So to find out for the x, you multiply 5 by 17 since everything is 17 times more.
5 x 17 = 85
The final ratio will be:
2:5 = 34:85
We can say that 17 times more snow has snowed that year since comparing the January snowfall, it shows that 34 is 17 times more of 2. So to predict the total snowfall, we multiply the 5 by 17, since like I said before, the amount of snowfall is 17 times more than before. Therefore, 5 multiplied by 17 equals to 85. The predicted total snowfall for the entire year will be 85 inches.