Find the median of the data:
3, 11, 7, 2, 5, 9, 9, 2, 10, 15, 7

Answer

To find the median of the given data set, we will follow these steps:

### Step 1: Arrange the data in ascending order
First, we need to arrange the numbers in the data set from the smallest to the largest. The given data is:
3, 11, 7, 2, 5, 9, 9, 2, 10, 15, 7

Arranging these numbers in ascending order, we get:
2, 2, 3, 5, 7, 7, 9, 9, 10, 11, 15

### Step 2: Count the number of observations
Next, we count how many numbers are in our arranged data set. The arranged data is:
2, 2, 3, 5, 7, 7, 9, 9, 10, 11, 15

There are a total of 11 observations.

### Step 3: Determine if the number of observations is odd or even
Since we have 11 observations, we note that this is an odd number.

### Step 4: Calculate the position of the median
For a data set with an odd number of observations, the median can be found using the formula:
Median = (n + 1) / 2
where n is the number of observations.

Substituting the value of n:
Median = (11 + 1) / 2 = 12 / 2 = 6

### Step 5: Find the median value
Now we need to find the 6th term in our arranged data set:
1st term: 2
2nd term: 2
3rd term: 3
4th term: 5
5th term: 7
6th term: 7

Thus, the median of the data set is 7.

### Final Answer
The median of the data set is **7**.

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