The middle most observation of every data arranged in order is called:
Mode
Median
Mean
Deviation
(2)
The middle most observation of every data arranged in order is called median.
The median of a given frequency distribution is found graphically with the help of:
Frequency curve
Bar graph
Histogram
An ogive
(4)
An ogive is a plot of the cumulative frequencies of a frequency distribution.
When the cumulative frequencies of class-intervals are plotted against upper or lower limits of class intervals, the graph obtained by joining the points by free hand forming smooth curve is called the cumulative frequency curve or ogive.
Ogive graphs are used to find the median of the given set of data.
The median of the following observations given in order 16, 18, 20, 24 − x, 22 + 2x, 28, 30, 32 is 24. The value of x is:
5
4
2
1
(3)
Given, median of the data 16, 18, 20, 24 − x, 22 + 2x, 28, 30, 32 is 24.
The mean and median of 50 and 35, respectively, where
(i) b - a = 10 (ii) a + c = 115 (iii) a = 20 (iv) b = 35
Choose the correct option from the following:
(i) and (iii)
(ii) and (iii)
(i) and (iv)
(ii) and (iv)
(4)
The empirical relation between the mode, median and mean of a distribution is:
Mode = 3 Median − 2 Mean
Mode = 3 Mean − 2 Median
Mode = 2 Median − 3 Mean
Mode = 2 Mean − 3 Median
(1)
We know that the empirical relation is given by,
Mode = 3 Median − 2 Mean
Using the empirical formula, the mode of a distribution whose mean is 8.32 and the median is 8.05, is equal to:
7.51
7.21
7.01
7.31
(1)
Given, mean = 8.32 and median = 8.05
∴ Mode = 3 × Median − 2 × Mean
= 3 × 8.05 − 2 × 8.32
= 24.15 − 16.64
= 7.51
The times in seconds, taken by 150 athletes to run a 110 m hurdle race are tabulated below:
| Class | 13.8–14 | 14–14.2 | 14.2–14.4 | 14.4–14.6 | 14.6–14.8 | 14.8–15 |
|---|---|---|---|---|---|---|
| Frequency | 2 | 4 | 5 | 71 | 48 | 20 |
The number of athletes who completed the race in or equal to 14.6 seconds is:
11
71
82
130
(3)
We have,
| Class | Frequency | Cumulative frequency |
|---|---|---|
| 13.8–14 | 2 | 2 |
| 14–14.2 | 4 | 6 |
| 14.2–14.4 | 5 | 11 |
| 14.4–14.6 | 71 | 82 |
| 14.6–14.8 | 48 | 130 |
| 14.8–15 | 20 | 150 |
From the above cumulative frequency table, 82 athletes completed the race in or equal to 14.6 seconds.
If the mode of the following data is K, then the value of K in the data set
9, 8, 6, 7, 1, 6, 10, 6, 7, K² − 12K + 42, 9, 7 and 13 is:
(i) 6 (ii) 9 (iii) 7 (iv) 13
Choose correct option from the following:
(iii) and (iv)
(i) and (iii)
Only (i)
(i) and (ii)
(2)
In the above dataset, value 6 and 7 have occurred most number of times, i.e., 3 times.
Also, mode = K.
So, either 6 or 7 would be the mode.
If K = 6,
If K = 7,
∴ K = 6 and K = 7
So, (i) and (iii) are correct.