Advertisements
Advertisements
Question
Find the mean of: 5, 2.4, 6.2, 8.9, 4.1 and 3.4
Solution
Mean of 5, 2.4, 6.2, 8.9, 4.1 and 3.4
Required mean = `("Sum of data values")/("No. of. data values")`
`= (5 + 2.4 + 6.2 + 8.9 + 4.1 + 3.4)/6`
`= 30/6`
= 5
APPEARS IN
RELATED QUESTIONS
The following table gives the frequency distribution of trees planted by different Housing Societies in a particular locality:
| No. of Trees | No. of Housing Societies |
| 10-15 | 2 |
| 15-20 | 7 |
| 20-25 | 9 |
| 25-30 | 8 |
| 30-35 | 6 |
| 35-40 | 4 |
Find the mean number of trees planted by Housing Societies by using ‘Assumed Means Method’
Consider the following distribution of daily wages of 50 worker of a factory.
|
Daily wages (in Rs) |
100 − 120 |
120 − 140 |
140 −1 60 |
160 − 180 |
180 − 200 |
|
Number of workers |
12 |
14 |
8 |
6 |
10 |
Find the mean daily wages of the workers of the factory by using an appropriate method.
The following table gives the number of children of 150 families in a village. Find the average number of children per family.
| No. of children (x) | 0 | 1 | 2 | 3 | 4 | 5 |
| No. of families (f) | 10 | 21 | 55 | 42 | 15 | 7 |
Find the mean from the following frequency distribution of marks at a test in statistics:
| Marks(x) | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 |
| No. of students (f) | 15 | 50 | 80 | 76 | 72 | 45 | 39 | 9 | 8 | 6 |
If the mean of the following distribution is 27, find the value of p.
| Class | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 |
| Frequency | 8 | p | 12 | 13 | 10 |
Find the mean using direct method:
| Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Frequency | 7 | 5 | 6 | 12 | 8 | 2 |
Find the mean marks per student, using assumed-mean method:
| Marks | 0 – 10 | 10 – 20 | 20 – 30 | 30 – 40 | 40 – 50 | 50 – 60 |
| Number of Students |
12 | 18 | 27 | 20 | 17 | 6 |
In an annual examination, marks (out of 90) obtained by students of Class X in mathematics are given below:
| Marks Obtained |
0 – 15 | 15 – 30 | 30 – 45 | 45 – 60 | 60 – 75 | 75 – 90 |
| Number of students |
2 | 4 | 5 | 20 | 9 | 10 |
Find the mean marks.
Which measure of central tendency is given by the x-coordinate of the point of intersection of the 'more than' ogive and 'less than' ogive?
Which of the following cannot be determined graphically?
The mean of n observation is `overlineX` .f the first item is increased by 1, second by 2 and so on, then the new mean is
If the mean of frequency distribution is 8.1 and Σfixi = 132 + 5k, Σfi = 20, then k =?
There are 45 students in a class, in which 15 are girls. The average weight of 15 girls is 45 kg and 30 boys is 52 kg. Find the mean weight in kg of the entire class.
The contents of 100 match box were checked to determine the number of match sticks they contained.
| Number of match sticks | Number of boxes |
| 35 | 6 |
| 36 | 10 |
| 37 | 18 |
| 38 | 25 |
| 39 | 21 |
| 40 | 12 |
| 41 | 8 |
(i) Calculate correct to one decimal place, the mean number of match sticks per box.
(ii) Determine how many matchsticks would have to be added. To the total contents of the 100 boxes to bring the mean up exactly 39 match sticks.
Find the mean of the following distribution:
| Class interval | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 |
| Frequency | 10 | 6 | 8 | 12 | 5 |
If the arithmetic mean of x, x + 3, x + 6, x + 9 and x + 12 is 10, then x = ?
A car travels from city A to city B, 120 km apart at an average speed of 50km/h. It then makes a return trip at an average speed of 60km/h. It covers another 120km distance at an average speed of 40km/h. The average speed over the entire 360km will be ______.
Find the values of x and y if the mean and total frequency of the distribution are 25 and 50 respectively.
| Class Interval | 0 – 10 | 10 – 20 | 20 – 30 | 30 – 40 | 40 – 50 | 50 – 60 |
| Frequency | 7 | x | 5 | y | 4 | 2 |
Find the mean of the following frequency distribution:
| Class | 1 – 5 | 5 – 9 | 9 – 13 | 13 – 17 |
| Frequency | 4 | 8 | 7 | 6 |
The mean of 6 distinct observations is 6.5 and their variance is 10.25. If 4 out of 6 observations are 2, 4, 5 and 7, then the remaining two observations are ______.
