Apart from pie charts, what statistical methods can represent data? Calculate angles for a pie chart and the population growth rate.

here are the answers for question 6:

SECTION B

6. (a) (i) Apart from pie charts, two other statistical methods that can be used to represent the data in the table are:

• Bar graphs
• Divided bar graphs

6. (a) (ii) Calculations for the pie chart:

Total population = 3,138,000

• Nairobi West: $$\frac{685,000}{3,138,000} \times 360^\circ = 0.2183 \times 360^\circ \approx \boxed{78.59^\circ}$$
• Nairobi East: $$\frac{1,144,000}{3,138,000} \times 360^\circ = 0.3646 \times 360^\circ \approx \boxed{131.26^\circ}$$
• Nairobi North: $$\frac{1,062,000}{3,138,000} \times 360^\circ = 0.3384 \times 360^\circ \approx \boxed{121.82^\circ}$$
• Westlands: $$\frac{247,000}{3,138,000} \times 360^\circ = 0.0787 \times 360^\circ \approx \boxed{28.33^\circ}$$

To draw the pie chart:

1. Draw a circle with a radius of 5 cm.
2. Using a protractor, measure and draw the calculated angles from the center of the circle.
3. Label each sector with the corresponding district name and its population size or percentage.

6. (a) (iii) Calculation of the population growth rate of Nairobi:

Population in 2009 = 3,138,000
Population in 1999 = 2,143,000
Time period = $2009 - 1999 = 10$ years

Population growth rate = $\frac{\text{Population in 2009} - \text{Population in 1999}}{\text{Population in 1999}} \times 100\%$

$$\frac{3,138,000 - 2,143,000}{2,143,000} \times 100\%$$ $$\frac{995,000}{2,143,000} \times 100\%$$ $$0.4643 \times 100\% \approx \boxed{46.43\%}$$

6. (b) Two factors that may have led to the large population increase in Nairobi between 1999 and 2009 are:

• Rural-urban migration: Many people moved from rural areas to Nairobi in search of better employment opportunities, higher wages, and improved social amenities like education and healthcare.
• Natural increase: The birth rate within Nairobi remained higher than the death rate, contributing to the overall population growth.

6. (c) Four positive effects of low population growth in a country are:

• Reduced pressure on resources: Lower demand for essential resources such as food, water, housing, and energy, leading to better resource management and sustainability.
• Improved provision of social services: Governments can more effectively provide quality education, healthcare, and infrastructure to a smaller, slower-growing population, enhancing the quality of life.
• Higher per capita income and living standards: With fewer people sharing the national wealth, the average income per person can increase, leading to better living standards and reduced poverty.
• Environmental benefits: Less strain on the environment due to reduced pollution, deforestation, and habitat destruction, contributing to ecological balance and biodiversity conservation.