CBSE Maths Class 7 Test from Data Handling and Probability

M.M: 48 marks                                                 Dated: 17/07/2011

Time: 1 hour 30 minutes

Q 1: Fill in the blanks (1 mark per question x 16 = 16 marks):

1. The difference between the highest and lowest observation is known as ______.
2. The ____ of a set of observations is the observation that occurs most often.
3. ______ refers to the value which lies in the middle of the data when arranged in increasing and decreasing order.
4. A _________ graph is a representation of numbers using bars of uniform widths.
5. A collection of numerical figures giving some particular type of information is called _______.
6. Each numerical figure in a data is called an ________.
7. _______ is the subject that deals with the collection, presentation, analysis and interpretation of numerical data.
8. If number of observations, i.e., N is odd, then median = _______________.

9. If number of observations, i.e., N is even, then median = _______________.
10. Formula to calculate mode when median and median are known is: Mode = 3 x _______ - 2 x _______.
11. In probability, an experiment in which each of the outcomes cannot be predicted in advance is called a ___________ experiment.
12. __________ data is the data which is collected by an investigator himself/herself with a definite plan or design.
13. One single group of a tally bars including the slanted one has total of ______ bars.
14.  ______ is the Greek letter showing summation.

15. A ______ is an action which results in one or several outcomes.
16. An ________ associated to a random experiment is the collection of some outcomes of the experiment.

Q 2: A die is thrown 100 times and the outcomes are noted as shown below:                                                                  (4 marks)

Outcome           1          2          3          4          5         6

Frequency        13        14        18        19        16        20

If the same die is now thrown at random, find the probability of getting a/an:

1. 3
2. 6
3. Even number
4. Multiple of 3

Q 3: A box contains three pairs of socks of two colours blue and grey. I have picked out a grey sock. I pick out one more sock with my eyes closed. What is the probability that I will make a pair?      (2 marks)

Q 4: Read the bar graph given below and answer the following questions:                                                                          (4 marks)

1. What information is represented by the bar graph?

2. In which year what the production minimum?

3. After which year was there a sudden fall in the production?

4. Find the ratio between the minimum production and the maximum production during the given period shown in the graph.

Q 5: The results of pass percentage of class Xth and class XIIth in CBSE examination of a school for 5 years are given in the following table.                                                                  (7 marks)

Year  --> Class	2000-01	2001-02	2002-03	2003-04	2004-05
X	96	94	96	86	95
XII	98	85	88	92	90

1. Draw the appropriate bar graph to represent the data.             (3 marks)
2. Whose average is more – class Xth or class XIIth? How much?         (2 marks)
3. In which year, was the difference of pass percentage between class Xth and class XII the least?        (1 mark)
4. For class XIIth, when was the decrease of pass percentage the most?         (1 mark)

Q 6: Calculate the mode and median of the following data:                      (4 marks)
       
11, 13, 11, 15, 14, 12, 13, 17, 18, 11, 13, 14, 15, 14, 15, 15, 14,  16, 12, 15, 15, 14, 14, 12, 14, 16, 14, 13, 14, 12, 14, 13.

Also, find the mean by using the empirical relation.

Q 7: Following table shows the number of shirts of different sizes 
        sold in a week by a shopkeeper.                             (2 marks)

Size of shirt (in inches)        34       36        38      40         42     44

Number of shirts sold          14       21        35      42          21      7

Which shirt size should the shopkeeper order to take care of the most of the customers ordering one particular size? Why?

Q 8: The following observations have been arranged in ascending order. If the median of data is 65, find the value of x.     (2 marks) 

30, 33, 49, 51, 3x, 3x+4, 73, 79, 85, 96.

Q 9: The weights in kg of 10 students are: 30, 32, 31, 29, 35, 30, 35, 28, 36, and 34. Find the median.                               (4 marks)

If the 36 kg weight is replaced by 27 kg and 32 kg weight is replaced by 37 kg, then find the new median.

Q 10: Find the value of “a” if the mean of the following distribution is 8.71.                                                             (3 marks)

x:   4         6                8                10                12                14

f:   7          9                16               a                  9                  5