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13.Statistics
normal
If each of given $n$ observations is multiplied by a certain positive number $'k'$, then for new set of observations -
A
variance will be unchanged.
B
new variance will be $k$ times old variance
C
standard deviation will be unchanged.
D
new standard deviation will be $k$ times old standard deviation
Solution
Variance will be multiplied by $k^2$.
$S.D$. will be multiplied by $k$.
Standard 11
Mathematics
Similar Questions
Find the mean and variance for the data
| ${x_i}$ | $92$ | $93$ | $97$ | $98$ | $102$ | $104$ | $109$ |
| ${f_i}$ | $3$ | $2$ | $3$ | $2$ | $6$ | $3$ | $3$ |
hard
Consider the statistics of two sets of observations as follows :
| Size | Mean | Variance | |
| Observation $I$ | $10$ | $2$ | $2$ |
| Observation $II$ | $n$ | $3$ | $1$ |
If the variance of the combined set of these two observations is $\frac{17}{9},$ then the value of $n$ is equal to ….. .
