Mean of grouped data : step deviation method - class-IX
Description: mean of grouped data : step deviation method | |
Number of Questions: 16 | |
Created by: Sangita Pandit | |
Tags: measures of dispersion measure of central tendency maths frequency distribution tables and graphs statistics |
The mean weight of 9 students is 24 kg. If one more student is joined in the group the mean is unaltered, then the weight of the 10th student is
The arithmetic mean in a measure of central tedency and is popularlyknown as mean. Arithmetic mean is obtained by dividing the sum of the values of all items of a series by the number of items of that series. Normally, arithmetic mean is denoted by $\bar X$ which is red as '$X$ bar'. It can be computed for unclassified or ungrouped data or individual series as well as classified or grouped data or discrete or continuous series.
Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
---|---|---|---|---|---|---|
No. of students | 10 | 20 | 30 | 50 | 40 | 30 |
The standard deviation and mean diameter of the circles respectively are
Following table gives frequency distribution of trees planted by different housing societies in a particular locality.
Find mean number of trees planted by housing society by using 'step deviation method'.
No. of tress | 10 - 15 | 15 - 20 | 20 - 25 | 25 - 30 | 30 - 35 | 35 - 40 |
---|---|---|---|---|---|---|
No. of Societies | 2 | 7 | 9 | 8 | 6 | 4 |
Following table gives age groupwise distribution of people suffering from 'Asthama' due to air pollution in certain city. Find mean age of person suffering from 'Asthama' .
Age (in years) | 7 - 11 | 11 - 15 | 15 - 19 | 19 - 23 | 23 - 27 | 27 - 31 | 31 - 35 | 35 - 39 |
---|---|---|---|---|---|---|---|---|
No. of People | 5 | 9 | 13 | 21 | 16 | 15 | 12 | 9 |
Find the arithmetic mean for the following grouped frequency distribution:
Class-intervals$ | $6-10$ | $10-14$ | $14-18$ | $18-22$ | $22-26$ | $26-30$ |
---|---|---|---|---|---|---|
Frequency | $ 4$ | $ 6$ | $9$ | $ 12$ | $ 7 $ | $2$ |
Following table shows frequency distribution of advertisement on T.V. by shift of origin ans scale method.
Duration (in sec.) | 25 - 30 | 30 - 35 | 35 - 40 | 40 - 45 | 45 - 50 | 50 - 55 |
---|---|---|---|---|---|---|
No. of advertisements | 10 | 32 | 15 | 9 | 7 | 2 |
Obtain mean duration of advertisement on T.V. by shift of origin and scale method.
Number of calories (in' 00) consumed daily by a sample of 15 years old boys are given below.
Calories | 1000 - 1500 | 1500 - 2000 | 2000 - 2500 | 2500 - 3000 | 3000 - 3500 | 3500 - 4000 | 4000 - 4500 |
---|---|---|---|---|---|---|---|
No. of boys | 5 | 13 | 16 | 18 | 27 | 10 | 4 |
Obtain mean calories consumed daily by a boy by step deviation method.
Consider the table given below
Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
---|---|---|---|---|---|---|
Number of Students | 12 | 18 | 27 | 20 | 17 | 6 |
The arithmetic mean of the marks given above is
The marks obtained by $20$ students of Class $X$ of a certain school in a English paper consisting of $100$ marks are presented in table below. Find the mean of the marks obtained by the students using step deviation method.
Find the arithmetic mean using step deviation method for the following data shows distance covered by $40$ passengers to perform their work. (Round off your answer to the nearest whole number).
Distance (km) | 1-5 | 5-9 | 9-13 | 13-17 | 17-21 | 21-25 | 25-29 |
---|---|---|---|---|---|---|---|
Number of passengers | 2 | 4 | 6 | 8 | 10 | 5 | 5 |
In a study on a certain population, the following data was given.
Population (X) | 2000-2001 | 2001-2002 | 2002-2003 | 2003-2004 | 2004-2005 | 2005-2006 | 2006-2007 |
---|---|---|---|---|---|---|---|
Number of people | 10 | 20 | 30 | 40 | 50 | 60 | 70 |
Find the average number of population using step deviation method.
The frequency distribution of marks in English are given in the table:
Marks | 50-60 | 60-70 | 70-80 | 80-90 |
---|---|---|---|---|
Number of students | 12 | 24 | 14 | 10 |
Find the mean by step deviation method.
Using step deviation method find the mean.
X | 20-40 | 40-60 | 60-80 | 80-100 |
---|---|---|---|---|
frequency | 4 | 8 | 12 | 16 |