Email

Chat with tutors

Login

Ask Questions, Get Answers

Menu X

home ask tuition questions practice papers mobile tutors pricing

X

Recent questions tagged variance-and-standard-deviation

For two variables $x$ and $y$ with the same mean the two regression lines are $x+2y-5=0$ $ 2x+3y-8=0$ and variance $(x)=12$ Then $ \sigma_y$ is

asked Mar 26, 2014 by balaji

1 answer

If SD of $X$ is $ \sigma $ then SD of $ \large\frac{aX+b}{c}$ ( where $a,b,c$ are constants ) is

asked Feb 1, 2014 by thanvigandhi_1

1 answer

If an experiment with 15 observations on $x$ the following results were available: $\Sigma x^2=2830 \: \Sigma x = 170$. One observation that was 20 was found to be wrong and was replaced by the correct value 30. The corrected variance is

asked Feb 1, 2014 by thanvigandhi_1

1 answer

If SD of 15 items is 6 and each item is decreased by 1, find the SD of the new set.

asked Jan 31, 2014 by thanvigandhi_1

1 answer

The first of the two sample has 100 items with mean 15 and S.D= 3. If the whole group has 250 items with mean 15.6 and SD = $ \sqrt{13.44}$ the S.D of the second group is?

asked Jan 31, 2014 by thanvigandhi_1

1 answer

If $r_{xy}$ between two variates $x$ and $y$ is 0.6 $ cov (x,y)=4.8\: \sigma_x^2=9$ then $\sigma_y$ is

asked Jan 31, 2014 by thanvigandhi_1

1 answer

The standard deviation of $n$ observations $x_1, x_2, ....x_n$ is 2. If $ \sum_{i=1}^n x_i=20$ and $ \sum_{i=1}^n x_i^2=100$ then $n$ is $i=1$

asked Jan 31, 2014 by thanvigandhi_1

1 answer

The standard deviation of the numbers 31, 32, 33, 46, 47 is

asked Jan 31, 2014 by thanvigandhi_1

1 answer

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

asked Jan 31, 2014 by thanvigandhi_1

1 answer

If $b_{yx}=1.6$ and $b_{xy}=0.4$ and the angle between two regression lines is $ \theta$ then $ \tan \theta$ is

asked Jan 29, 2014 by thanvigandhi_1

1 answer

If the coefficient of variation of a distribution is 45% and the mean is 12 then its standard deviation is

asked Jan 29, 2014 by thanvigandhi_1

1 answer

The mean of the numbers $ a, b, 8, 5, 10$ is $6$ and the variance is $6.80$. Then which one of the following gives possible values of $a$ and $b$ ?

asked Jan 29, 2014 by thanvigandhi_1

1 answer

For two data sets each of size 5, the variances are given to be 4 and 5 and the corresponding means are given to be 2 and 4 respectively. The variance of the combined data set is

asked Jan 28, 2014 by thanvigandhi_1

1 answer

The standard deviation of -1, -2, -3, -4, -5, -6, -7 is

asked Jan 28, 2014 by thanvigandhi_1

1 answer

The two lines of regression are $ x+2y-5=0$ and $ x+3y-8=0$. The coefficient of correlation between $x$ and $y$ is

asked Jan 28, 2014 by thanvigandhi_1

1 answer

If $r_1$ and $r_2$ are regression coefficients of $y$ on $x$ and $x$ on $y$ respectively

asked Jan 28, 2014 by thanvigandhi_1

1 answer

The coefficient of correlation between $x$ and $y$ is $0.5$ and their covariance is $16$ and SD of $x$ is $4$ then SD of $y$ is

asked Jan 28, 2014 by thanvigandhi_1

1 answer

For 12 pair of observation on $x$ and $y$ the $r$ calculated is $0.674$. The standard error is

asked Jan 28, 2014 by thanvigandhi_1

1 answer

If the SD of X is $\sigma_X$ then SD of $\large\frac{aX-b}{c}$ ( where a,b,c are constants ) is:

asked Jan 27, 2014 by thanvigandhi_1

1 answer

The correlation between $x$ and $a-x$ is

asked Jan 27, 2014 by thanvigandhi_1

1 answer

To see more, click for the full list of questions or popular tags.

Feedback Terms Facebook Twitter About Us

Your payment for is successful.

...