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The mean of x(1)+x(2)+…+x(n) is M. When ...

The mean of `x_(1)+x_(2)+…+x_(n)` is M. When `x_(i) ,i=1,2,….,10,` is replaced by `x_(i)+10`, the mean is `M_(1)`. Then `M_(1)` =

A

M

B

`M+10`

C

10 M

D

`M+100`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we need to understand the concept of mean and how it changes when we modify the values in the dataset. ### Step-by-Step Solution: 1. **Understanding the Mean**: The mean of a set of numbers \( x_1, x_2, \ldots, x_n \) is given by the formula: \[ M = \frac{x_1 + x_2 + \ldots + x_n}{n} \] Here, \( n \) is the total number of terms. In this case, we have \( n = 10 \) and the mean is \( M \). 2. **Replacing Values**: We are told that each \( x_i \) (where \( i = 1, 2, \ldots, 10 \)) is replaced by \( x_i + 10 \). Therefore, the new values become: \[ x_1 + 10, x_2 + 10, \ldots, x_{10} + 10 \] 3. **Calculating the New Mean**: The new mean \( M_1 \) can be calculated as: \[ M_1 = \frac{(x_1 + 10) + (x_2 + 10) + \ldots + (x_{10} + 10)}{10} \] 4. **Simplifying the New Mean**: We can simplify the expression for \( M_1 \): \[ M_1 = \frac{(x_1 + x_2 + \ldots + x_{10}) + (10 \times 10)}{10} \] Here, \( 10 \times 10 \) accounts for the 10 added to each of the 10 terms. 5. **Substituting the Original Mean**: We know from the original mean \( M \): \[ x_1 + x_2 + \ldots + x_{10} = 10M \] Therefore, substituting this into the equation for \( M_1 \): \[ M_1 = \frac{10M + 100}{10} \] 6. **Final Calculation**: Simplifying the above expression: \[ M_1 = M + 10 \] ### Conclusion: The new mean \( M_1 \) after replacing each \( x_i \) with \( x_i + 10 \) is: \[ M_1 = M + 10 \]
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Knowledge Check

  • The mean of x_(1),x_(2)....... x_(50) is M, if every x_ị, i = 1, 2 ..... 50 is replaced by x_(i)//50 then the mean is

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    `M+(1)/50`
    C
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    B
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    C
    `(nM-x_(n)+x')/(n)`
    D
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