Statistics

1.The median of a data can graphically be found from

(i) an ogive,

(ii) a histogram,

(iii) a frequency curve,

(iv) a bar graph.

2.The relationship among the three measures of central tendency i.e., median, mode and mean can be represented as

3. The median of a data is 5. The mean of the same data is 7. Find the mode of the data.
4. What is the median of a dataset whose mean and mode are 36 and 18 respectively?
5. The following table shows frequency distributions of a few observations. The mode of the observations is 42. The missing frequency p is not the greatest frequency. Find the value of p?

Class interval	Frequency
10 – 19	9
20 – 29	8
30 – 39	12
40 – 49	16
50 – 59	p
60 – 69	11
70 – 79	15

6. The following table lists the frequency distribution of 30 observations. The mean of the data is 48. The value of [f1 − f2] is

       Class interval  0 − 20                  20 − 40          40 – 60           60 – 80               80 – 100

         Frequency (fi)     8                        f1                      6                       4                      f2

 

7. The following frequency distribution table shows the class marks of continuous class Intervals of 40 observations. What is the median of the given dataset?

Class mark	Frequency
10	5
30	7
50	6
70	9
90	6
110	7

8. The following data represents a frequency distribution of 90 observations whose median is 125. What is the median of the given data set?

Height (in cm)	Number of children in locality
More than 100	90
More than 110	81
More than 120	76
More than 130	68
More than 140	60
More than 150	48
More than 160	33
More than 170	20
More than 180	3

9. What is the median of the given data set? What are the respective values of x and y?
  

Score	Frequency
Less than 30 Less than 60 Less than 90 Less than 120 Less than 150 Less than 180 Less than 210	7    15    27    27 + x    36 + x    36 + x + y    46 + x + y
Total	65

10. The following data lists the ranges of marks obtained (out of 100) by 60 students of a class. What are the marks scored by more than half of the students?
 

Marks	Number of students
0 – 10	2
10 – 20	1
20 – 30	3
30 – 40	5
40 – 50	7
50 – 60	11
60 – 70	10
70 – 80	9
80 – 90	5
90 – 100	7

11. The given frequency distribution table lists the weights of students of two different Grades What is the difference between the modal weights of class IX and X?

Weight(kg)	Number of students in classIX	Number of students in classX
40 – 45 45 – 50 50 – 55 55 – 60 60 – 65 65 – 70	10      12       8      11      10       6	12           10            5           14           11            6

Prepared By:
Mr. Vijay Chawla
Email [email protected]
9899114400