A Preview of Lesson 5.7
The graphing calculator is a powerful tool for observing patterns and analyzing data that comes from research or experimentation. Many of the measures of variation you will learn about in Lesson 5-7 can be calculated by using a graphing calculator.
Before analyzing any data, you must know how to enter it into a list.
Example 1: The Glencoe Publishing Golf Tournament is held every September to raise money for a scholarship fund. The list below includes the scores for the employees fo the manufacturing department. Enter the data and find the range of these scores.
First enter the data. Method 1 Assign the data to List 1 (L1) from the home screen. Enter: { 139 , 99 , 105 , 115 , 88 , 91 , 105 , 80 , 102 , 101 , 103 , 95 , 99 , 77 , 112 } Method 2 Enter the data directly into the list display. Before entering your data, you must clear the L1 list of previously entered data. Enter: 4 Enter each score into the L1 list. Enter: 1 The cursor appears int he L1 list. Enter the data one by one pressing after each entry, including the last one. Then find the range. The range of teh scores is the difference of the maximum and minimum values in the list. Enter: 2 ) - 1) The range of the data is 62.
First enter the data.
Method 1 Assign the data to List 1 (L1) from the home screen.
Enter: { 139 , 99 , 105 , 115 , 88 , 91 , 105 , 80 , 102 , 101 , 103 , 95 , 99 , 77 , 112 }
Method 2 Enter the data directly into the list display.
Before entering your data, you must clear the L1 list of previously entered data.
Enter: 4
Enter each score into the L1 list.
Enter: 1
The cursor appears int he L1 list. Enter the data one by one pressing after each entry, including the last one.
Then find the range.
The range of teh scores is the difference of the maximum and minimum values in the list.
Enter: 2 ) - 1)
The range of the data is 62.
The data can be arranged into four groups that have approzimately the same number of data in each group. The points separating these groups are called quartiles and are symbolized by Q1, Q2, and Q3. The median of the set is Q2. The interquartile range is Q3 - Q1. Half of the data lies in this range. You can use a graphing calculator to help you find each of these measures.
Example 2: Find the quartiles and the interquartile range of the golf data in Example 1.
Before finding the measures you want, you must first make sure the calculator is set to refer to the correct set of data. Our data is in L1.
Enter: 3 and highlight L1 under 1-var stats. Make sure that the frequency is 1. Enter: 1
Enter: 3 and highlight L1 under 1-var stats. Make sure that the frequency is 1.
Use the down arrow key to scroll to the end of the statistics. This tells you there are 15 items of data, the least value (minX) is 77, the greatest value (maxX) is 139, the lower quartile (Q1) is 91, the median is 101, and the upper quartile (Q3) is 105.
Use Q3 and Q1 to find the interquartile range: Q3 - Q1 = 105 - 91 = 14
For Practice: Do Exercises at the end of section 5-7A
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