1. Find the range of the heights of 12 girls in a class given in centimeters.

120, 110, 150, 100, 130, 145, 150, 100, 140, 150, 135, 125.

2. The number of chocolates eaten by children in 5 families are 4, 6, 8, 12, and 15. Find their Standard Deviation.

3. The scores of a cricketer in 7 matches are 70, 80, 60, 50, 40, 90, and 95. Find the Standrad Deviation.

4. Find the Standard Deviation and the Variance of the following:-

x 10 15 18 20 25

f 3 2 5 8 2

5. Find the Variance of the following data:

Variable 10 6 18 14 22 2

Frequency 10 7 7 15 6 5

6. Calculate the Standard Deviation for the following distribution:

C.I 0-10 10-20 20-30 30-40 40-50

f 3 13 21 15 5

7. Calculate the Standard Deviation for the following distribution:

C.I 0-10 10-20 20-30 30-40

f 4 7 8 3

8. The largest value of a data is 98. If the range of the data is 78, find the smallest value of the data.

9. Find the Standard deviation of the following data:- 30, 80, 20, 40, 50, 70, 60.

Add 5 to each term and find the new Standard Deviation.

10.The Standard Deviation of 5 values is 12. If each value in increased by 6, find the Standard Deviation and Variance of the new set of values.

11. The Variance of 5 values is 36. If each value is doubled, find the Standard Deviation of the new values.

12. Three coins are tossed simultaneously. What is the probability of getting a minimum of one head?

13. A perfect dice is tossed twice. Find the probability of getting 9.

14. A card is drawn from a well shuffled pack of 52 cards after replacement. Find the probability of

(a) getting a red card

(b) getting a King

(c) getting a black ace

(d) getting King of heart.

(e) getting a card of club.

15.What is the probability that a number selected from the first 25 natural numbers is a prime number?

16. A coin is tossed twice. Find the probability of getting exactly one head.

17. Find the probability of getting a prime number when a die is thrown.

18. What is the probability that a leap year selected at random will have 53 Sundays?

19. A two digit number is formed with the digits 3, 5, and 7 without repetition of digits. Find the probability that the number so formed would be greater than 57.

20. Two dice are thrown together. Find the probability that the two digit number formed with the two numbers turning up is divisible by 3.