The expression 12g
gives the number of kilometers a car can travel using g liters of gasoline. how far can this car travel on 5 1/2 liters of gasoline?

The median of a data set is the measure of center that is found by adding the data values and dividing the total by the number of data values that is the value that occurs with the greatest frequency that is the value midway between the maximum and minimum values in the original data set that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude