A grouped frequency distribution table with class intervals of equal size ………… 250 270 (270 not included in this interval) as one of the class intervals is constructed for the following data:
268, 220, 368, 258, 242, 310, 272, 342, 310, 290, 300, 320, 319, 304, 402, 318, 406 ………..
(a) 4
(b) 5
(c) 6
(d) 7
Solution:
(c) 6 is correct
The mean of x- 1, x + 1, x + 3 and x + 5 is…….
Solution:
(b) x + 2
The mean of five numbers is 30. If one number is excluded, their mean ….. The excluded number is……
Solution:
Let a,b,c,d and e are five numbers
mean = (a +b+ c+ d+e)/5 = 30
⇒ (a +b+ c+ d+e) = 150_______(1)
now, Let the number excluded be a
then, new mean = (b+ c+ d+e)/4 = 28
⇒ (b+ c+ d+e)= 112
putting this value in (1),
⇒a + 112 = 150
⇒a = 150 -112 = 38
∴ excluded number = 38 is correct
More Solutions:
- The area under wheat cultivation last year in the following states.
- Given below is the data of percentage of passes:
- Number of students (boys and girls) in class IX of a certain school:
- Frequency distribution of monthly wages of 255 workers of a factory.
- Histogram for the following frequency distribution:
- Draw a histogram for the following data:
- Draw a frequency polygon for the following data:
- The marks obtained in a weekly test were as under:
- In a city, the weekly observations made in a study.