The marks of 9 students are: 16, 20, 24, 27, 31, 36, 39, 42, 48. If the marks of the student who scored 48 are replaced by 52, what is the value of the new median?
31
For an odd number n of observations arranged in ascending order, the median is the \(\left(\frac{n + 1}{2}\right)\)th observation.
Here n = 9, so the median is the \(\frac{9 + 1}{2} = 5\)th observation.
After replacing 48 by 52, the marks in ascending order are 16, 20, 24, 27, 31, 36, 39, 42, 52; the largest value only changed, so the order of the first eight values is unaffected.
Therefore the new median is the 5th value, 31.
Check: in 16, 20, 24, 27, 31, 36, 39, 42, 52 there are four values (16, 20, 24, 27) below 31 and four values (36, 39, 42, 52) above it, so 31 is the middle value.
Hence, 31.
Find the weighted mean of 15, 20 and 25 with weights 2, 3 and 5, respectively.
The mean, median, and mode satisfy the empirical relation, Mode = 3×Median – 2×Mean. If the mean is increased by 5 while the median remains unchanged, then the new mode, will:
In an exam, marks scored by 16 students of section A (out of 50) are 33, 41, 56, 51, 53, 46, 49, 41, 45, 56, 51, 49, 46, 41, 53, 33 and marks scored by 13 students of section B (out of 50) are 47, 54, 42, 50, 47, 39, 42, 52, 56, 49, 54, 39, 47. Calculate the difference between the mode of section B and section A.
For a distribution, the empirical relation is, Mode = 3×Median – 2×Mean. If the Mean and Median satisfy, \(20 \le \text{Mean} \le 25\) and \(20 \le \text{Median} \le 25\), what is the possible range of the Mode?
The following figures give the temperature (in °C) of city X for a week in the month of March. Find the arithmetic mean (in °C) of the temperatures by the direct method.
Temperature recorded: 32.3, 34.5, 33.1, 32.7, 35.3, 33.2, 34.1
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The median of a symmetric distribution is 32 and the mode is 29. What is the mean?
The mode of a dataset is 25. Which of the following datasets has 25 as the unique mode?
The mean of a distribution is 72, and the mean exceeds the mode by 12. In this distribution, the value (Mean - Median) is one-third of (Mean - Mode). Find the median.
A random sample of 20 people is classified in the following table according to their ages:
Age | Frequency |
15 – 25 | 2 |
25 – 35 | 4 |
35 – 45 | 6 |
45 – 55 | 5 |
55 - 65 | 3 |
What is the mean age of this group of people?
The median of the following observations 46, 64, 87, 41, 58, 77, 35, 90, 55, 92, 33 is 58. If 92 is replaced by 99 and 41 by 43 in the above data. The new median is:
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If the mode of the scores 10, 12, 13, 15, 15, 13, 12, 10, x is 15, then what is the value of x?