Embibe Experts Solutions for Chapter: Statistics, Exercise 2: Exercise-2

The average marks of $10$ students in a class was $60$ with standard deviation $4.$ While the average marks of other $10$ students was $40$ with a standard deviation $6.$ If all the $20$ students are taken together, their standard deviation will be

The mean and variance of $5$ observations of an experiment are $4$ and $5.2$, respectively. From these observations three are $1, 2$ and $6$ and $\lambda =\left|x_1-x_2\right|+8$ where $x_1 \& x_2$ are remaining observations, then number of solution of equation $10-x^2-2x=\lambda$ are

The mean and variance of $10$ numbers were calculated as $11.3$ and $3.3$, respectively. It was subsequently found that one of the number was misread as $10$ instead of $12.$ How does the variance change?

STATEMENT-1 : $\sum _{i=1}^9\left(x_i-8\right)=9$ and $\sum _{i=1}^9{\left(x_i-8\right)}^2=45$, then S.D. of $x_1, x_2, \dots \dots , x_9$ is $2$

STATEMENT-2 : S.D. is independent of change of origin

STATEMENT-I : Mean cannot be represented graphically.

STATEMENT-II : Mean may not coincide with anyone of the actual values.

If the daily earnings (in rupees) of $12$ workers in a factory are $16, 11, 3, 7, 5, 28, 9, 31, 28, 43, 15, 17,$ then which of the following is(are) true?

If first sample of $25$ variates has the mean $40$ and standard deviation $5$ and a second sample of $35$ variates has the mean $45$ and standard deviation $2,$ then which of the following is/are true

Which of the following is false?