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Statement-1 : The variance of the variat...

Statement-1 : The variance of the variates 112, 116, 120,125,132 about their A.M. is 48.8.
Statement-2 : `sigma=sqrt((Sigma_(i=1)^(n) f_i(x_i-barx)^2)/(Sigma_(i=1)^(n) f_i)`

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To solve the problem, we need to verify the statements regarding the variance of the given variates and the formula for variance. Let's go through the steps systematically. ### Step 1: Calculate the Arithmetic Mean (A.M.) The arithmetic mean (A.M.) is calculated using the formula: \[ \text{A.M.} = \frac{\text{Sum of observations}}{\text{Number of observations}} \] The observations given are: 112, 116, 120, 125, 132. Calculating the sum: \[ \text{Sum} = 112 + 116 + 120 + 125 + 132 = 605 \] Number of observations (n) = 5. Now, substituting into the formula: \[ \text{A.M.} = \frac{605}{5} = 121 \] ### Step 2: Calculate the Variance Variance is calculated using the formula: \[ \text{Variance} = \frac{\sum (x_i - \bar{x})^2}{n} \] Where \(x_i\) are the observations and \(\bar{x}\) is the mean we calculated. Now, we calculate each term \((x_i - \bar{x})^2\): 1. For \(x_1 = 112\): \[ (112 - 121)^2 = (-9)^2 = 81 \] 2. For \(x_2 = 116\): \[ (116 - 121)^2 = (-5)^2 = 25 \] 3. For \(x_3 = 120\): \[ (120 - 121)^2 = (-1)^2 = 1 \] 4. For \(x_4 = 125\): \[ (125 - 121)^2 = (4)^2 = 16 \] 5. For \(x_5 = 132\): \[ (132 - 121)^2 = (11)^2 = 121 \] Now, summing these squared differences: \[ \text{Sum of squared differences} = 81 + 25 + 1 + 16 + 121 = 244 \] Now, substituting into the variance formula: \[ \text{Variance} = \frac{244}{5} = 48.8 \] ### Conclusion From our calculations, we find that the variance of the variates 112, 116, 120, 125, and 132 about their A.M. is indeed 48.8. Therefore, Statement-1 is true. ### Statement-2 Verification The formula given in Statement-2 is: \[ \sigma = \sqrt{\frac{\sum_{i=1}^{n} f_i (x_i - \bar{x})^2}{\sum_{i=1}^{n} f_i}} \] This is indeed the correct formula for calculating the standard deviation when considering frequency distributions. In our case, since all observations have a frequency of 1, the formula simplifies to the one we used for variance. ### Final Answer Both Statement-1 and Statement-2 are true. ---
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