If `x_(1), x_(2),`"…......." `x_(18)` are observation such that `sum_(j=1)^(18)(x_(j) -8) = 9` and `sum_(j=1)^(18)(x_(j) -8)^(2) = 45`, then the standard deviation of these observations is

Options

A. `sqrt((81)/(34))`
B. 5
C. `sqrt(5)`
D. `(3)/(2)`

Explanation

To find the standard deviation of the observations \( x_1, x_2, \ldots, x_{18} \), we will follow these steps:

### Step 1: Understand the given information
We are given:
1. \( \sum_{j=1}^{18} (x_j - 8) = 9 \)
2. \( \sum_{j=1}^{18} (x_j - 8)^2 = 45 \)

### Step 2: Calculate the mean
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