CPM Homework Help : A2C Problem 3-128

When data is arranged from least to greatest, the middle number (or the number between the two middle numbers, in the case of an even number of data pieces) is the median. The median of the lower half of data determines the boundary of the first and second quartiles. The median of the upper half of data determines the boundary of the third and fourth quartiles. The scores for $12$ golfers were as follows: $68$ , $73$ , $80$ , $95$ , $86$ , $68$ , $74$ , $72$ , $90$ , $85$ , $70$ , and $82$ . Find the scores in the third quartile.

Step 1:

First order the values from least to greatest.

Step 2:

Now find the where the median would be and separate the values and ignore the lesser half.

Step 3:

Now find the median of the remaining values and ignore the upper half.

Answer:

The remaining values ( $80$ , $82$ , and $85$ ) are the scores in the third quartile.