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

Total Questions: 50

11. In a frequency distribution, the mid value of a class is 12 and its width is 6. The lower limit of the class is [RRB NTPC 05/01/2021 (Morning)]

Correct Answer: (b) 9
Solution:

12. The sum of the class marks of the classes 90–120 and 120–150 is [RRB NTPC 05/01/2021 (Evening)]

Correct Answer: (b) 240
Solution:

13. If the mean is 25 and the standard deviation is 5 then the coefficient of variation is: [RRB NTPC 07/01/2021 (Evening)]

Correct Answer: (a) 20%
Solution:

14. The mean of a, b, c, d, e and f is 36. If the mean of b, d and f is 28, find the mean of a, c and e. [RRB NTPC 08/01/2021 (Evening)]

Correct Answer: (c) 44
Solution:

15. The following are the weights (in kg) of 25 students, 58, 55, 53, 50, 53, 51, 52, 54, 53, 52, 54, 53, 58, 53, 59, 55, 53, 52, 51, 54, 53, 59, 55, 53, 52. What is the weight (in kg) of the heaviest student? [RRB NTPC 09/01/2021 (Morning)]

Correct Answer: (a) 59
Solution:

= The weight of the heaviest student is 59 kg.

16. The following are the weights (in kg) of 25 students, 58, 55, 53, 50, 53, 51, 52, 54, 53, 52, 54, 53, 58, 53, 59, 55, 53, 52, 51, 54, 53, 59, 55, 53, 52. What is the most commonly observed weight (in kg)? [RRB NTPC 09/01/2021 (Morning)]

Correct Answer: (c) 53
Solution:

The most commonly observed weight is 53 kg.

17. The following are the weights (in kg) of 25 students. 58, 55, 53, 50, 53, 51, 52, 54, 53, 52, 54, 53, 58, 53, 59, 55, 53, 52, 51, 54, 53, 59, 55, 53, 52. Among the following options, what is the weight (in kg) that appears least number of times in the given data? [RRB NTPC 09/01/2021 (Morning)]

Correct Answer: (a) 50
Solution:

The weight (in kg) that appears the least number of times in the given data is 50 kg.

18. The following are the weights (in kg) of 25 students. 58, 55, 53, 50, 53, 51, 52, 54, 53, 52, 54, 53, 58, 53, 59, 55, 53, 52, 51, 54, 53, 59, 55, 53, 52. What is the range of the given data? [RRB NTPC 09/01/2021 (Morning)]

Correct Answer: (c) 9
Solution:

The range of the given data is (Max weight - Min weight) = (59 - 50) = 9

19. If the mean of the following data is 11, find the value of k. 11, 19, 5, 10, k, 13, 12, 8, 15, 14 [RRB NTPC 10/01/2021 (Morning)]

Correct Answer: (a) 3
Solution:

20. Find the missing value of p for the following distribution, whose mean is 12.58 [RRB NTPC 11/01/2021 (Morning) ]

Correct Answer: (a) 15
Solution: