The number of miles my car can go on a gallon of gasoline is normally distributed with a mean of 30 miles and a standard deviation of 4 miles. i currently have exactly one gallon in my tank, and have to travel 35 miles to my destination.
1. what is the probability i make it to my destination before i run out of gas?
2. find the distance d so that i have a 90% chance of traveling d miles before running out of gas (assuming again that i start with one gallon).
3. suppose i can change my mean mileage per gallon by adjusting the carburetor. what value should i set the mean to so that i have a 90% chance of making it 35 miles on one gallon of gas?