The 2014 winner of the Boston Marathon runs as many as 120 miles per week. During the last few weeks of his training for an event, his mileage can be modeled by M(w) = 120(.90)^{w 1}, where w represents the number of weeks since training began. Which statement is true about the model M(w)?

1) The number of miles he runs will increase by 90% each week.

2) The number of miles he runs will be 10% of the previous week.

3) M(w) represents the total mileage run in a given week.

4) w represents the number of weeks left until his marathon.