R D Sharma Solutions for Chapter: Statistics, Exercise 9: MULTIPLE CHOICE QUESTIONS (MCQs)

A batsman scores runs in $10$ innings as $38, 70, 48, 34, 42, 55, 63, 46, 54$ and $44$. The mean deviation about mean 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

The mean of $100$ observations is $50$ and their standard deviation is $5$. The sum of all squares of all the observations is
 

Let $x_1,x_2,\dots ,x_n$ be $n$ observations. Let $y_1=a{x}_i+b$ for $i=1,2,\dots ,n$, where $a$ and $b$ are constants. If the mean of $i=1,2,\dots ,n$, is 48 and their stand ard deviation is $12$, the mean of $y_i^{\text{'}s}$ is $55$ and standard deviation of $y_i^{\text{'s }}$ is $15$ the values of $a$ and $b$ are

The mean deviation of the data $3, 10, 10, 4, 7, 10, 5$ from the mean is

The mean deviation for $n$ observations $x_1, x_2, \dots , x_n$ from their mean $\overline{X}$ is given by

Let $x_1,x_2,\dots ,x_n$ be $n$ bservations and $\overline{X}$ be their arithmetic mean. The standard deviation is given by

The standard deviation of the observations $6, 5, 9, 13, 12, 8, 10$ is