The question asks for the standard deviation of the first 7 natural numbers, which are 1, 2, 3, 4, 5, 6, 7.
The mean ($\mu$) is the average of the numbers.
Numbers = {1, 2, 3, 4, 5, 6, 7}
Number of observations (N) = 7
Mean ($\mu$) = $\frac{1+2+3+4+5+6+7}{7} = \frac{28}{7} = 4$
Variance ($\sigma^2$) is the average of the squared differences from the Mean.
Sum of squared differences = $9 + 4 + 1 + 0 + 1 + 4 + 9 = 28$
Variance ($\sigma^2$) = $\frac{\text{Sum of squared differences}}{N} = \frac{28}{7} = 4$
The standard deviation ($\sigma$) is the square root of the variance.
Standard Deviation ($\sigma$) = $\sqrt{\text{Variance}} = \sqrt{4} = 2$
Therefore, the standard deviation of the first 7 natural numbers is 2.
If the probability of winning a match is 0.7, then what is the value of variance ?
Match items of List - I with that of List - II and select the correct option using the codes given below :
| List – I | List – II | ||
|---|---|---|---|
| (a) | Coefficient of variation | (i) | Square root of the average of the squared deviation measured from mean. |
| (b) | Standard deviation | (ii) | Absolute measure of dispersion around median. |
| (c) | Mean deviation | (iii) | Variation of the distribution adjusted with mean in percentage. |
| (d) | Quartile deviation | (iv) | Average of the absolute deviation of scores from a measure of central tendency. |
| (v) | Under root of the squared value of maximum variance from mean. | ||
Codes :