Diagrams, charts and graphs
Diagrams, charts and graphs

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Diagrams, charts and graphs

2.2.1 Try some yourself

Activity 7

Consider the table about household sizes.

  • (a) What was the total number of households surveyed in 1971?

  • (b) How many of the households surveyed in 1991 consisted of three people?

  • (c) What is the total for the 1981 column?

Answer

  • (a) The total number of households surveyed in 1971 was 18.6 million.

  • (b) The table shows that 16% of the households surveyed in 1991 consisted of three people. The actual number of such households was 16% of 22.4 million, which is 3.584 million.

  • (c) The total for the 1981 column is 22 + 32 + 17 + 18 + 7 + 4 = 100.

Activity 8

Consider the table about families with dependent children.

  • (a) What percentage of families have a single parent?

  • (b) What percentage of families are couples with 2 or more dependent children?

Answer

  • (a) The percentage of families with a lone mother is 19%

  • The percentage of families with a lone father is 2%

  • Hence the percentage of families with a singleparent is 19% + 2% = 21%

  • (b) The percentage of families that are couples with 2 dependent children is 37% and

  • The percentage of families that are couples with 3 or more dependent children is 25%.

  • Hence the percentage of families that are couples with 2 or more dependent children is 37% + 25% = 62%.

Activity 9

Below is a table summarising the cigarette-smoking habits of a sample of men in various age groups.

Number of cigarettes Percentage of each age group
smoked per day 16–24 25–34 35–49 50–59 60 or over All aged over 16
None 62 52 52 50 60 55
1–20 18 19 20 21 24 22
Over 20 19 29 28 28 16 23
Number of men surveyed 1850 2560 2470 1960 2150 10 990
  • (a) Write down the percentage of men aged between 25 and 34 who smoke over 20 cigarettes a day.

  • (b) How many of the men aged 60 or over are non-smokers?

  • (c) Which age group has the highest percentage of heavy smokers?

Answer

  • (a) Find ‘25–34’ in the column headings; then look down this column to the ‘Over 20’ row. This gives 29%.

  • (b) The ‘60 or over’ column shows that 60% of men aged 60 or over do not smoke, and that the total number of men aged 60 or over in the sample is 2150. So 60% of 2150 = 1290 of the men aged 60 or over are non-smokers.

  • (c) Suppose a ‘heavy smoker’ is defined as one who smokes more than 20 cigarettes per day. Then, less than 20% of men in the 16–24 age group and the 60 and over group are heavy smokers. In the 25–34, 35–49 and 50–59 age groups, well over 20% are heavy smokers. So these are the age groups with the higher percentages of heavy smokers, with the age range 25–34 having marginally the highest.

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