The smallest value in your data is your minimum. The greatest value is your maximum. In order to calculate the other three terms you asked for, you need to put your data in numerical order, and find the median. The median is the middle value. After putting your data in numerical order (smallest to greatest) (you have an odd number of values in your data), your eighth number is your median.
1, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 10
If you place, parenthesis around the first set of data before your median, this set, will be used to find your first quartile. If you place parenthesis around the last set of data after your median, this set will be used to find your third quartile.
(1, 4, 4, 4 , 5, 5, 6), 6, (6, 6, 7, 7 , 8, 8, 10)
The median of the lower set of data, is the value of the first quartile, also known as Q1. Here it is a 4.
The median of the upper set of data, is the value of the third quartile, also known as Q3. Here it is a 7.
So your five number summary is as follows:
Min = 1, Q1 = 4, Med = 6, Q3 = 7, Max = 10