#### Descriptive Statistics and Probability Model Question Paper

11th Standard

Reg.No. :
•
•
•
•
•
•

Time : 01:30:00 Hrs
Total Marks : 50
6 x 1 = 6
1. Which of the following is positional measure?

(a)

Range

(b)

Mode

(c)

Mean deviation

(d)

Percentiles

2. The best measure of central tendency is

(a)

Arithmetic mean

(b)

Harmonic mean

(c)

Geometric mean

(d)

Median

3. The geometric mean of two numbers 8 and 18 shall be

(a)

12

(b)

13

(c)

15

(d)

11.08

4. The median of 10,14,11,9,8,12,6 is

(a)

10

(b)

12

(c)

14

(d)

9

5. The first quartile is also known as

(a)

median.

(b)

lower quartile.

(c)

mode.

(d)

third decile

6. Probability of an impossible event is

(a)

1

(b)

0

(c)

0.2

(d)

0.5

7. 7 x 2 = 14
8. A person purchases tomatoes from each of the 4 places at the rate of 1kg., 2kg., 3kg., and 4kg. per rupee respectively .On the average, how many kilograms has he purchased per rupee?

9. The price of a commodity increased by 5% from 2004 to 2005, 8% from 2005 to 2006 and 77% from 2006 to 2007. Calculate the average increase from 2004 to 2007?

10. A man travelled by car for 3 days. He covered 480 km each day. On the first day he drove for 10 hours at 48 km an hour. On the second day, he drove for 12 hours at 40 km an hour and for the last day he drove for 15 hours at 32 km. What is his average speed?

11. A die is thrown twice and the sum of the number appearing is observed to be 6. What is the conditional probability that the number 4 has appeared at least once?

12. There are 1000 students in a school out of which 450 are girls. It is known that out of 450, 20% of the girls studying in class XI. A student is randomly selected from 1000 students. What is the probability that the selected student is from class XI given that the selected student is a girl?

13. Let P(A)=$\frac{3}{5}$ and P(B)=$\frac{1}{5}$ . Find P(A∩B) if A and B are independent events.

14. Data on readership of a magazine indicates that the proportion of male readers over 30 years old is 0.30 and the proportion of male reader under 30 is 0.20. If the proportion of readers under 30 is 0.80. What is the probability that a randomly selected male subscriber is under 30?

15. 5 x 3 = 15
16. Find D2 and D6 for the following series 22, 4, 2, 12, 16, 6, 10, 18, 14, 20, 8

17. Compute Q1, D2 and P90 from the following data

 Marks 10 20 30 40 50 60 No. of Students 4 7 15 8 7 2
18. Calculate Harmonic Mean for the following data given below

 Value 0-10 10-20 20-30 30-40 40-50 Frequency 8 12 20 6 4
19. Calculate GM for the following table gives the weight of 31 persons in sample survey.

 Weight (lbs): Frequency 130 135 140 145 146 148 149 150 157 3 4 6 6 3 5 2 1 1
20. Calculate the mean deviation about median and its relative measure for seven numbers given below: 55, 45, 40, 20, 60, 80, and 30.

21. 3 x 5 = 15
22. Verify the relationship among AM, GM and HM for the following data

 X 7 10 13 16 19 22 25 28 f 10 22 24 28 19 9 12 16
23. Calculate quartile deviation and its relative measure from the following data:

 X f 0-10 10-20 20-30 30-40 40-50 50-60 5 10 13 18 14 8
24. Three coins are tossed simultaneously. Consider the events A ‘three heads or three tails’, B ‘atleast two heads’ and C ‘at most two heads’ of the pairs (A, B), (A, C) and (B, C), which are independent? Which are dependent?