To find out how many people would be expected to receive a coupon for sleigh rides, we can use the concept of expected value. Since there are three equally likely outcomes (skiing, snow tubing, or sleigh rides), the probability of receiving any one type of coupon is:
\[ P(\text{sleigh rides}) = \frac{1}{3} \]
If 900 people participate, we can calculate the expected number of people receiving a coupon for sleigh rides as follows:
\[ \text{Expected number for sleigh rides} = \text{Total participants} \times P(\text{sleigh rides}) \] \[ = 900 \times \frac{1}{3} = 300 \]
Thus, we would expect 300 people to receive a coupon for sleigh rides.