a) There are four stages that impact the childbirth rate:

Stage 1: High birth and high death rates - Factors such as early marriages, widespread illiteracy, traditional customs, unawareness about family planning techniques, children as a source for supplementing family income etc. contributed to high birth rates. Lack of adequate diets and medical and sanitation facilities resulted in high rate of deaths.

Stage 2: High birth rate and fall in the death rate: High birth rate and fall in the death rate resulted in tremendous increase in population. Due to economic development, the living as well as medical and sanitation conditions improved resulting in fall in death rates.

Stage 3: Fall in the birth rate and low death rate: Fall in the birth rate and low death rate resulted in fall in population. Factors such as shift in the economy from agrarian to an industrialised one, understanding the importance of small size family, growing urbanisation etc. resulted in fall in the birth rate.

Stage 4: Low birth and death rate: Low birth and death rate resulted in a very little growth in population or stationary population. Factors such as higher standard of living, high rate of literacy, urbanization etc. contributed to the overall economic development and leading to low birth and death rate.

b) Family planning encompass numerous advantages along with preventing the damage caused by high risk and undesired pregnancies. Family planning provides benefits to mother, children, father, and the family. Post delivery health of the women can improve and it gives women more time for her family and own personal advancement. Family planning result in improved maternal and child health, but also social and economic development, education, and women’s empowerment.  

c) Natural Increase between Both Years = Number of births-Number of deaths

= 3,985,423 - 3,895,146 = 90,277

Net Migration between Both Years = (Population in 2019-Population in 2018)- (Number of births-Number of deaths)

= (910,258, 848 - 908,840,812)-(3,985,423 - 3,895,146) = 1,327,759

Crude Birth rate= (Number of resident live births / Number of total population) x 1,000

=3,985,423 / (910,258, 848)*1000 = 4.38

Crude Death rate= (Number of resident deaths / Number of total population) x 1,000

=3,895,146 / (910,258, 848 )*1000 = 4.28

Crude Rate of Natural Increase (%)= Crude Birth Rate - Crude death rate

= 4.38-4.28 = 0.10

Crude Growth Rate= 0.001559

P₂₀₁₉ = P₂₀₁₈ * e^rt

910,258,848 = 908,840,812 * e^r(1)

910,258,848 /908,840,812 = e^r(1)

ln(910,258,848)-ln(908,840,812) = r

r =20.62924-20.62768 = 0.001559