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

Total Questions: 50

21. In a frequency distribution, if the mid-value of the class is 35 and the value of the lower boundary is 30, then the value of its upper boundary is: [RRB NTPC 09/03/2021 (Evening)]

Correct Answer: (c) 40
Solution:

22. If the mode of a series is greater than its mean by 9, then find the difference between the mode and the median. [RRB NTPC 11/03/2021 (Morning)]

Correct Answer: (b) 6
Solution:

23. In a frequency distribution, the frequency of the observations 2, 4, 8, 7, and 5 is 5, 3, 2, 6, and 4, respectively. Find the arithmetic mean of this data. [RRB NTPC 11/03/2021 (Evening)]

Correct Answer: (a) 5
Solution:

24. Calculate the standard deviation for the following data. 4, 7, 9, 10, 15 [RRB NTPC 12/03/2021 (Morning)]

Correct Answer: (d) 3.633
Solution:

25. Calculate the standard deviation for the following data. 3, 4, 5, 6, 7 [RRB NTPC 14/03/2021 (Morning)]

Correct Answer: (c) √2
Solution:

26. The mean of 5 observations is 20. If another observation is added, then the mean increases by 2. What is the value of the 6th observation that is added? [RRB NTPC 14/03/2021 (Evening)]

Correct Answer: (b) 32
Solution:

27. The values of the mode and the mean are 25.2 and 27.5 respectively in a moderately asymmetrical distribution. Find the value of the median of the distribution. [RRB NTPC 15/03/2021 (Morning)]

Correct Answer: (a) 26.73
Solution:

28. If the mean of six observations 5, 7, 9, α, 11 and 12 is 9, then the value of α is: [RRB NTPC 15/03/2021 (Evening) ]

Correct Answer: (d) 10
Solution:

29. The variance of the seven observations 6, 7, 10, 12, 13, 8, 14 is: [RRB NTPC 19/03/2021 (Morning)]

Correct Answer: (d) 8.29
Solution:

30. Find the difference between the mean and the median of the following data set: 2, 3, 4, 5, 5, 8, 8 [RRB NTPC 21/03/2021 (Morning)]

Correct Answer: (d) 0
Solution: