Amrita thinks of a number. She doubles it, adds 9 , divides her answer by 3 and finally subtracts 1 . She obtains the same number she originally thought of. What was Amrita's number?

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