Statistics (Class 9,Math)

1. The class mark of the class 90-130 is:

2. The range of the data:
25, 81, 20, 22, 16, 6, 17,15,12, 30, 32, 10, 91, 8, 11, 20 is

3. In a frequency distribution, the mid value of a class is 10 and the width of the class is 6. The upper limit of the class is:

4. The width of each of five continuous classes in a frequency distribution is 5 and the lower class-limit of the lowest class is 10. The lower class-limit of the highest class is:

5. Let m be the mid-point and 1 be the lower class limit of a class in a continuous frequency distribution. The upper class limit of the class is:

6. The class marks of a frequency distribution are given as follows:
15, 20, 25, …
The class corresponding to the class mark 15 is:

7. In the class intervals 10-20, 20-30, the number 20 is included in:

8. A grouped frequency table with class intervals of equal sizes using 250-270 (270 not included in this interval) as one of the class interval is constructed for the following data:
268, 220, 368, 258, 242, 310, 272, 342, 310, 290, 300, 320, 319, 304,402, 318, 406, 292, 354, 278, 210, 240, 330, 316, 406, 215, 258, 236.
The frequency of the class 370-390 is:

9. A grouped frequency distribution table with classes of equal sizes using 63-72 (72 included) as one of the class is constructed for the following data:
30, 32, 45, 54, 74, 78, 108, 112, 66, 76, 88, 40, 14, 20, 15, 35, 44, 66, 75, 84, 95, 96, 102, 110, 88, 74, 112, 14, 34, 44.
The number of classes in the distribution will be:

10. To draw a histogram to represent the following frequency distribution:

the adjusted frequency for the class 25-45 is:

11. The mean of five numbers is 30. If one number is excluded, their mean becomes 28. the excluded number is:

12. If x¯ represents the mean of n observations x₁, x₂, …, x_n, then value of ∑ni=1(xi−x¯) is:

13. If each observation of the data is increased by 5, then their mean

14. Let x¯ be the mean of x₁, x₂, …, x_n and y the mean of y₁, y₂, …, y_n. If z is the mean of x₁, x₂, …. x_n, y₁, y₂, …, y_n, then z is equal to

15. The median of the data
78, 56, 22, 34, 45, 54, 39, 68, 54, 84 is

16. For drawing a frequency polygon of a continous frequency distribution, we plot the points whose ordinates are the frequencies of the respective classes and abcissae are respectively:

17. Mode of the data
15, 14, 19, 20, 16, 15, 16, 14, 15, 18, 14, 19, 16, 17, 16 is

18. The mean of 25 observations is 26. Out of these observations if the mean of first 13 observations is 22 and that of the last 13 observations is 30, the 13th observation is: