For Use with Lesson 11-7
ACTIVITY
Suppose you want to know the mean number of letters in the last names of everyone listed in your local phone book. You could count the letters in every last name, but that is not very practical. Instead, you could approximate this mean by taking a sample of last names and finding the mean number of letters in only those names.
Activity 1
Step 1 | Copy the table above. Extend the table to go to Sample 20. |
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Step 2 | Without looking, open a phone book to a random page. Place your index finger on the page, still without looking. Then, count the number of letters in the name closest to the tip of your finger. Record this number in the table in the first blank space for Sample 1. Close the phone book. |
Step 3 | Repeat Step 2 and record this number in the table in the second blank space for Sample 1. These two numbers make up one sample. Find the mean and record it in the table. |
Step 4 | Collect a total of 20 samples by repeating Steps 2 and 3. |
Step 5 | Copy the grid above and use the means from Data Set A to make a bar graph. |
Step 6 | Make a second table with space for 10 numbers in each of the 20 samples. Label this table Data Set B. |
Step 7 | Repeat Steps 2 and 3, but now select 10 names for each sample. Record the data in the second table. |
Step 8 | Copy the grid again and use the means in Data Set B to make a bar graph. |