NDA | Mathematics | Frequency Distribution

Which one of the following can be considered as an appropriate pair of values of regression coefficient of y on x and regression coefficient of x on y?

Consider the following statements :

1) Variance is unaffected by change of origin and change of scale.

2) Coefficient of variance is independent of the unit of observations.

Which of the statements given above is/are correct?

The value of  for the following distribution is

Marks group: 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45

No of Student: 5       6       15      10       5       4        2       1

Find standard deviation of the above data.

In a partially destroyed record the following data are available :

Regression equation of x on y and regression equation of y on x are 3x+y=12 and x+2y=14 respectively then find the sum of mean values of x and y.