Find the mean and variance for the data

 $$x_i$$ 6 10 14 18 24 28 30 $$f_i$$ 2 4 7 12 8 4 3

Asked by Abhisek | 11 months ago |  82

Solution :-

$$Mean , \overline{X} = \dfrac{\displaystyle\sum_{i=1}^{7} f_i x_i}{N}$$

$$N= \displaystyle\sum_{i=1}^{n} f_i$$

$$\overline{X}$$ = $$\dfrac{760}{40}$$

= 19

Now, Variance

$$σ^2=\dfrac{1}{N} \displaystyle\sum_{i=1}^{7} f_i (X_i-\overline {X} )^2$$

$$\dfrac{1}{40}\times 1736$$

= 43.4

Answered by Abhisek | 11 months ago

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