Q1. The mean of 10 observations is 20. If one observation is removed, the mean
becomes 18. Find the removed observation.
Ans:-38
Q2. Find the median of the following data:
3, 7, 9, 12, 15, 18, 21
Ans:-12
Q3. The mean of the first 50 natural numbers is:
Ans:-25.5
Q4. What happens to the mean of a data set if every observation is multiplied by 3?
Ans:- Mean becomes 3 times
Q5. Which measure of central tendency is most affected by extreme values?
Ans:-Mean
Q6. The variance of a data set is 16. Find the standard deviation.
Ans:- 4
Q7. If the mean of x, y, z is 10 and x = 8, y = 12, find z.
Ans:-10
Q8. What is the mode of the data:
2, 4, 6, 8, 6, 4, 6?
Ans:-6
Q9. A coin is tossed once. What is the probability of getting a head?
Ans:- ½ or 0.5
Q10. A die is thrown once. Find the probability of getting:
a) A prime number
b) A number greater than 4
Ans:- a)½ or 0.5 (2,3,5 are primes)
b)⅓
Q11. Two coins are tossed together. What is the probability of getting at least one
tail?
Ans:-¾