If for distribution of 18 observations `sum(x_i-5)=3a n dsum(x_i-5)^2=43 ,` find the mean and standard deviation.

Explanation

To solve the problem step by step, we need to find the mean and standard deviation of the given distribution of 18 observations based on the provided information.

### Given:
1. \( \sum (x_i - 5) = 3 \)
2. \( \sum (x_i - 5)^2 = 43 \)
3. Number of observations, \( n = 18 \)

### Step 1: Find the sum of the observations \( \sum x_i \)
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