G Tewani Solutions for Chapter: Statistics, Exercise 1: Exercises

If the coefficient of variation of two distributions are $50$ and $60$, and their arithmetic means are $30$ and $25$ respectively, then the difference of their standard deviation is

The mean of $n$ terms is $\overline{x}$. If the first term is increased by $1$, second by $2$ and so on, then the new mean is

When tested, the lives (in $\mathrm{hours}$) of $5$ bulbs were noted as follows: $1357, 1090, 1666, 1494, 1623$
The mean deviations (in $\mathrm{hours}$) from their mean is

Following are the marks obtained by $9$ students in a mathematics test: $50, 69, 20, 33, 53, 39, 40, 65, 59$. The mean deviation from the median is

Let $r$ be the range and $S^2=\frac{1}{n-1}\sum _{i=1}^n{\left(x_i-\overline{x}\right)}^2$ be the of a set of observations $x_1, x_2,\dots ,x_n,$ then

If the mean of $100$ observations is $50$ and their standard deviation is $5$, then the sum of all squares of all the observations is

Consider the numbers $1, 2, 3, 4, 5, 6, 7, 8, 9, 10$. If $1$ is added to each number, the variance of the numbers so obtained is

Consider the first $10$ positive integers. If we multiply each number by $–1$ and then add $1$ to each number, the variance of the numbers so obtained is