Hand written solution required

Suppose that we fit a model to predict whether a person will go on a summer holiday ('Yes' or 'No') based on X, their savings as a percentage of their income. Upon surveying a large population, we discover that a ~ 45 for people who were going on vacation, and at = 10 for people who were not. In addition, the variance of X for both sets of people was o = 25. Finally 60% of the population is going on vacation. At what percentage of savings will we start predicting that a person will take a break this summer