5.2. Ungrouped Data to Find the Mean http://www.ck12.org
Now that the data has been organized, the numbers of books read and the numbers of students who read the books
are evident. The mean can now be calculated as it was in Example A:
x=∑
x 1 f 1 +x 2 f 2 +x 3 f 3 +...+xnfn
f 1 +f 2 +f 3 +...+fn
x=∑( 0 )( 1 )+( 1 )( 6 )+( 2 )( 8 )+( 3 )( 10 )+( 4 )( 13 )+( 5 )( 8 )+( 6 )( 5 )+( 7 )( 6 )+( 8 )( 3 )
1 + 6 + 8 + 10 + 13 + 8 + 5 + 6 + 3
x=∑^0 +^6 +^16 +^30 +^52 +^40 +^30 +^42 +^24
60
x=240
60
x= 4The mean number of books read by each student was 4 books.
Example C
Using technology, determine the mean of the following set of numbers:
24 , 25 , 25 , 25 , 26 , 26 , 27 , 27 , 28 , 28 , 31 , 32
Technology is a major tool that is available for you to use when doing mathematical calculations, and its use goes
beyond entering numbers to perform simple arithmetic operations. For example, the TI-83 calculator can be used to
determine the mean of a set of given data values. You will first learn to calculate the mean by simply entering the
data values into a list and determining the mean. The second method that you will learn about utilizes the frequency
table feature of the TI-83.
Step 1:
Step 2: