Statistics practice · Easy

The variance of first 50 even natural numbers is

The intersecting point of two regression lines is

The AM of the series $1,2,4,8,16, \ldots ,{2^n},$ is

The mode of a moderately symmetrical series is 18 and mean is 24 . The median is

The mean of a set of 30 observations is 75 . If each other observation is multiplied by a non-zero number $\lambda$ and then each of them is decreased by 25 , their mean remains the same. The $\lambda$ is equal to

The coefficient of variation of two series are 70 and 90 and their standard deviation are 17.5 and 18 , respectively. The mean of two series are

The mean of the numbers $a,\,\,b,\,\,8,\,\,5,\,\,10$ is 6 and their variance is 6.8. If $M$ is the mean deviation of the numbers about the mean, then $25 M$ is equal to:

If the two regression coefficients are 0.8 and 0.2 , then the coefficient of correlation is

Mean of 100 observation is 45. If it was later found that two observations 19 and 31 were incorrectly recorded as 91 and 13. The correct mean is

If mode of a data is 27 and mean is 24 , then median is

Quartile deviation is nearly equal to

In a moderately skewed distribution, the values of mean and median are 5 and 6 , respectively. The value of mode for such distribution is

If the variance of 1, 2, 3, 4, 5, ..., 10 is $\frac{{99}}{{12}}$, then the standard derivation of 3, 6, 9, 12, ..., 30 is

The coefficient of variation of two series are $58 \%$ and $69 \%$. If their standard deviations are 21.2 and 15.6 , then their A.Ms are

Mode of the data $3,2,5,2,3,5,6,6,5,3,5,2,5$ is-

The co-efficient of rank correlation of marks obtained by 10 students in Statistics and Accountancy was found to be 0.2 . It was later discovered that the difference in ranks in the two subjects obtained by one of the students was wrongly taken as 9 instead of 7 . The correct value of co-efficient of rank correlation is

Let the mean and the variance of 5 observations $x_1$, $x_2, x_3, x_4, x_5$ be $\frac{24}{5}$ and $\frac{194}{25}$ respectively. If the mean and variance of the first 4 observation are $\frac{7}{2}$ and a respectively, then $\left(4 a+x_5\right)$ is equal to

Given the following results for the height $(x)$ and weight (y) in appropriate units of 1000 students: $\bar{x}=68$, $\bar{y}=150, \sigma_x=2.5, \sigma_y=20, r=0.60$.
The height of a student A who weights 200 units is

If $x$ and $y$ are independent variables, then two lines of regression are

If the variables with values 10, 20, 30, 40 have frequencies $x, x+2, x-2, x+4$ and the mean is 2.7 then the value of $x$ is

If the mean and variance of six observations 7, 10, 11, 15, $a$, $b$ are 10 and $\frac{{20}}{3}$ respectively, then the value of $\left| {a - b} \right|$ is equal to

If in a frequency distribution, the mean and median are 25 and 26 , then its mode is approximately.

The number of runs scored by 11 players of a cricket team of school are $5,19,42$, $11,50,30,21,0,52,36,27$. The median is-

The values of mean, median and mode coincide, then the distribution is

If a variate $X$ is expressed as a linear function of two variates ${\cal U}\;and\;\;V$ the form $X = a\;{\cal U} + b\;V,$ then mean $\bar X\;of\,X$ is

Let the sum of the first three terms of an A. P, be 39 and the sum of its last four terms be 178 . If the first term of this A.P. is 10 , then the median of the A.P. is :

If $\sum\limits_{{i=1}}^{18}\left(x_i-8\right)=9$ and $\sum\limits_{{i=1}}^{18}\left(x_i-8\right)^2=45$ then the standard deviatioin of $x_1, x_2 \ldots \ldots x_{18}$ is

The weighted mean of the first $n$ natural numbers if their weights are the same as the numbers, is

If the mean and variance of the following data: 6, 10, 7, 13, a, 12, b, 12 are 9 and $\frac{{37}}{4}$ respectively, then ${(a - b)^2}$ is equal to

The sum of the four arithmetic means between 4 and 40 is