Mean, Median & Mode (Railway Maths) (Part – IV)

Total Questions: 50

11. Calculate the variance from the following data: 3, 6, 5, 2, 4 [RRB NTPC 02/03/2021 (Evening) ]

Correct Answer: (b) 2
Solution:

12. If the mean of five observations x, x − 1, x − 2, x − 3 and x − 4 is 20, then the mean of the first two observations is.. [RRB NTPC 03/03/2021 (Morning)]

Correct Answer: (c) 21.5
Solution:

13. Mean of first ten odd natural numbers is: [RRB NTPC 03/03/2021 (Evening)]

Correct Answer: (a) 10
Solution:

14. Find the arithmetic mean of 36, 53, 50, 43, 57, 50, 40, 35, 39 and 34. [RRB NTPC 04/03/2021 (Evening)]

Correct Answer: (a) 43.7
Solution:

15. The mean of 11 numbers is 44. If the mean of the first 6 numbers is 39 and that of the last 6 numbers is 48, then what is the 6th number? [RRB NTPC 04/03/2021 (Evening)]

Correct Answer: (a) 38
Solution:

16. Find the median of 7, 14, 13, 12, 20, 11, 15 and 8. [RRB NTPC 04/03/2021 (Evening)]

Correct Answer: (c) 12.5
Solution:

17. The mean of 20 observations is 50. It was later found that two observations 13 and 24 were incorrectly recorded as 31 and 42. The correct mean is: [RRB NTPC 05/03/2021 (Morning)]

Correct Answer: (d) 48.20
Solution:

18. Find the median of 45, 76, 32, 58, 16, 27, 64 and 35. [RRB NTPC 05/03/2021 (Morning) ]

Correct Answer: (b) 40
Solution:

19. Find the mean of the following data. 8, -2, 9, 6, 13, 17, 12 [RRB NTPC 05/03/2021 (Evening) ]

Correct Answer: (c) 9
Solution:

20. A frequency polygon is drawn using______. [RRB NTPC 07/03/2021 (Morning) ]

Correct Answer: (c) midpoint of classes and frequencies.
Solution:

A frequency polygon is drawn using the midpoint of classes and frequencies. A frequency polygon is a visual representation of a distribution. The visualization tool is used to understand the shape of a distribution