Ncert Solutions Maths class 11th

30. The mean and standard deviation of six observations are 8 and 4, respectively. If each observation is multiplied by 3, find the new mean and new standard deviation of the resulting observations.

29. The mean and variance of 7 observations are 8 and 16, respectively. If five of the observations are 2, 4, 10, 12, 14. Find the remaining two observations.

Class 11 Maths Statistics Miscellaneous exercise Solution

28. The mean and variance of eight observations are 9 and 9.25, respectively. If six of the observations are 6, 7, 10, 12, 12 and 13, find the remaining two observations.

27. The sum and sum of squares corresponding to length x (in cm) and weight y (in gm) of 50 plant products are given below:

${\displaystyle \sum _{i=1}^{50}=x_i=212,}{\displaystyle \sum _{i=1}^{50}{x}_i^2=902.8,{\displaystyle \sum _{i=1}^{50}{y}_i=261,}}{\displaystyle \sum _{i=1}^{50}{y_i}^2=1457.6}$

Which is more varying, the length or weight?

26. The following is the record of goals scored by team A in a football session:

For the team B, mean number of goals scored per match was 2 with a standard deviation 1.25 goals. Find which team may be considered more consistent?

24. From the prices of shares X and Y below, find out which is more stable in value:

Class 11 Maths Statistics exercise 13.3 Solution

23. From the data given below state which group is more variable, A or B?

Class 11 Maths Statistics exercise 13.3 Solution

23. From the data given below state which group is more variable, A or B?

22. The diameters of circles (in mm) drawn in a design are given below:

Calculate the standard deviation and mean diameter of the circles.

[ Hint First make the data continuous by making the classes as 32.5-36.5, 36.5-40.5, 40.5-44.5, 44.5 - 48.5, 48.5 - 52.5 and then proceed.]