Amit M Agarwal Solutions for Chapter: Statistics, Exercise 4: Entrances Gallery

The mean of five observations is $4$ and their variance is $5.2$. If three of these observations are $1,2$ and $6$, then the other two are 

The $\mathrm{A}.\mathrm{M}.$ of $9$ terms is $15$. If one more term is added to this series, then the $\mathrm{A}.\mathrm{M}.$ becomes $16$. The value of the added term is 

If the median of $\frac{x}{5},x,\frac{x}{4},\frac{x}{2},\frac{x}{3}\left(x>0\right)$ is $8$, then the value of $x$ is

If the standard deviation of $3,8,6,10,12,9,11,10 12,7$ is $2.71$, then the standard deviation of $30,80,60,100,120,90,110,100,120,70$ is

Coefficient of variation of two distributions are $50\%$ and $60\%$ and their arithmetic means are $30$ and $25$, respectively. Difference of their standard deviation is

Mean deviation of $6, 8, 12, 15, 10, 9$ through mean is

If the value observed are $1,2,3,\dots ,n$ each with frequency $1$ and $n$ is even, then the mean deviation from mean equals

The mean and variance of $n$ observations $x_1,x_2,x_3,\dots ,x_n$ are $5$ and $0$, respectively. If $\sum _{i=1}^n{x}_i^2=400$, then the value of $n$ is equal to