The mean marks (out of 100) of boys and girls in an examination are 70 and 73,
respectively. If the mean marks of all the students in that examination is 71, find
the ratio of the number of boys to the number of girls.
The following are the marks (out of 100) of 60 students in mathematics.
16, 13, 5, 80, 86, 7, 51, 48, 24, 56, 70, 19, 61, 17, 16, 36, 34, 42, 34, 35, 72, 55, 75,
31, 52, 28,72, 97, 74, 45, 62, 68, 86, 35, 85, 36, 81, 75, 55, 26, 95, 31, 7, 78, 92, 62,
52, 56, 15, 63,25, 36, 54, 44, 47, 27, 72, 17, 4, 30.
Construct a grouped frequency distribution table with width 10 of each class starting
from 0 – 9.
Two sections of Class IX having 30 students each appeared for mathematics olympiad. The marks obtained by them are shown below:
46 31 74 68 42 54 14 61 83 48 37 26 8 64 57
93 72 53 59 38 16 88 75 56 46 66 45 61 54 27
27 44 63 58 43 81 64 67 36 49 50 76 38 47 55
77 62 53 40 71 60 58 45 42 34 46 40 59 42 29
Construct a group frequency distribution of the data above using the classes 0-9, 10-19 etc., and hence find the number of students who secured more than 49 marks.
What is a population pyramid?
(a) A graphical presentation of the age, sex composition of a
population.
(b) When the population density of an area is so high that people live
in tall buildings.
(c) Pattern of population distribution in large urban areas.
The points scored by a basket ball team in a series of matches are as follows:
17, 2, 7, 27, 25, 5, 14, 18, 10, 24, 48, 10, 8, 7, 10, 28
Find the median and mode for the data.
Which are three main factors that cause population change?
(a) Births, deaths and marriage
(b) Births, deaths and migration
(c) Births, deaths and life expectancy
Which does the term population distribution refer to?
(a) How population in a specified area changes over time.
(b) The number of people who die in relation to the number of people
born in a specified area.
(c) The way in which people are spread across a given area.
Complete the sentences below using some of the following words.
sparsely, favourable, fallow, artificial, fertile, natural, extreme, densely
When people are attracted to an area it becomes …………………..
populated
Factors that influence this include ………………….. climate; good
supplies of ………………….. resources and ………………….. land.