If the variance of a data is 121 ,then the standard deviation of the data is ….. .

Options

A. `11`
B. 12
C. 10
D. 9

Explanation

To find the standard deviation from the given variance, we can follow these steps:

### Step 1: Write down the given information
The variance of the data is given as 121.

### Step 2: Recall the relationship between variance and standard deviation
The standard deviation (SD) is the square root of the variance (Var). This can be expressed as:
\[ \text{SD} = \sqrt{\text{Var}} \]

### Step 3: Substitute the value of variance into the formula
Now, substituting the given variance into the formula:
\[ \text{SD} = \sqrt{121} \]

### Step 4: Calculate the square root
Next, we calculate the square root of 121:
\[ \sqrt{121} = 11 \]

### Step 5: State the final answer
Thus, the standard deviation of the data is:
\[ \text{Standard Deviation} = 11 \]

### Summary of the Solution
The standard deviation of the data is 11.

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