Are the mean and median always nearly equal?

No, not always. Sometimes they are equal. Sometimes they are close to each other, but not exactly the same. Sometimes they are very different. It depends on the numbers that are being used to calculate the mean and median. The way each is calculated is different. The mean is got by adding all the numbers and dividing by the amount of numbers. The median is got by arranging the numbers in order and finding the middle value in the list, if there is an odd amount of numbers, or the value half way between the two middle values when there are an even amount of numbers.