Class 7th - Data handling Question bank

Data handling 

1. Ashish studies for 4 hours, 5 hours and 3 hours respectively on three consecutive days. How many hours does he study daily on an average?
2. A batsman scored the following number of runs in six innings: 36, 35, 50, 46, 60, 55 Calculate the mean runs scored by him in an inning.
3. The ages in years of 10 teachers of a school are: 32, 41, 28, 54, 35, 26, 23, 33, 38, 40

(i) What is the age of the oldest teacher and that of the youngest teacher?

(ii) What is the range of the ages of the teachers?

(iii) What is the mean age of these teachers?

4. Find the mean of the first five whole numbers.
5. The marks (out of 100) obtained by a group of students in a science test are 85, 76, 90, 85, 39, 48, 56, 95, 81 and 75. Find the:

(i) Highest and the lowest marks obtained by the students.

(ii) Range of the marks obtained.

(iii) Mean marks obtained by the group.

6. The enrolment in a school during six consecutive years was as follows:

1555, 1670, 1750, 2013, 2540, 2820   Find the mean enrolment of the school for this period.

7. The heights of 10 girls were measured in cm and the results are as follows:

135, 150, 139, 128, 151, 132, 146, 149, 143, 141.

(i) What is the height of the tallest girl? (ii) What is the height of the shortest girl?

(iii) What is the range of the data? (iv) What is the mean height of the girls?

(v) How many girls have heights more than the mean height.

8. Find the mode of the given set of numbers: 1, 1, 2, 4, 3, 2, 1, 2, 2, 4
9. Following are the margins of victory in the football matches of a league.

1, 3, 2, 5, 1, 4, 6, 2, 5, 2, 2, 2, 4, 1, 2, 3, 1, 1, 2, 3, 2,6, 4, 3, 2, 1, 1, 4, 2, 1, 5, 3, 3, 2, 3, 2, 4, 2, 1, 2

Find the mode of this data.

10. Find the mode of the numbers: 2, 2, 2, 3, 3, 4, 5, 5, 5, 6, 6, 8
11. Heights (in cm) of 25 children are given below:

168, 165, 163, 160, 163, 161, 162, 164, 163, 162, 164, 163, 160, 163, 16, 165,163, 162, 163, 164, 163, 160, 165, 163, 162

What is the mode of their heights? What do we understand by Mode here?

12. The scores in mathematics test (out of 25) of 15 students is as follows: 19, 25, 23, 20, 9, 20, 15, 10, 5, 16, 25, 20, 24, 12, 20 Find the mode and median of this data. Are they same?
13.  The runs scored in a cricket match by 11 players is as follows: 6, 15, 120, 50, 100, 80, 10, 15, 8, 10, 15

Find the mean, mode and median of this data. Are the three same?

14. The weights (in kg.) of 15 students of a class are: 38, 42, 35, 37, 45, 50, 32, 43, 43, 40, 36, 38, 43, 38, 47

(i) Find the mode and median of this data.

(ii) Is there more than one mode?

15. Find the mode and median of the data: 13, 16, 12, 14, 19, 12, 14, 13, 14 Tell whether the statement is true or false:

(i) The mode is always one of the numbers in a data.

(ii) The mean can be one of the numbers in a data.

(iii) The median is always one of the numbers in a data.

(iv) A data always has a mode.

(v) The data 6, 4, 3, 8, 9, 12, 13, 9 has mean 9.

16. A mathematics teacher wants to see, whether the new technique of teaching she applied after quarterly test was effective or not. She takes the scores of the 5 weakest children in the quarterly test (out of 25) and in the half yearly test (out of 25) Draw the bar chart of the following Observation .

Students         Ashish             Arun               Kavish            Maya              Rita

Quarterly       10                    15                    12                    20                    9

Half yearly     15                    18                    16                    21                    15

17. . Consider this data collected from a survey of a colony.

Favourite Sport         Cricket           Basket Ball     Swimming      Hockey           Athletics

Watching                     1240                470                  510                  423                  250

Participating                620                  320                  320                  250                  105

(i) Draw a double bar graph choosing an appropriate scale. What do you infer from the bar graph?

(ii) Which sport is most popular?

(iii) Which is more preferred, watching or participating in sports?

18. There are 6 marbles in a box with numbers from 1 to 6 marked on each of them.

(i) What is the probability of drawing a marble with number 2?

(ii) What is the probability of drawing a marble with number 5?

19. A coin is flipped to decide which team starts the game. What is the probability that your team will start?
20. A box contains pairs of socks of two colours (black and white). I have picked out a white sock. I pick out one more with my eyes closed. What is the probability that it will make a pair?