Francophone Africa (Cote d'Ivoire, Cameroon, Senegal) · ENSEA Abidjan, ISSEA Yaounde and ENSAE Dakar with ENSAE Paris · pg · unverified source
Common written competitive exams for statistician-economist engineer (ISE), statistics analyst and statistical technician streams, held in many African countries (reported).
Built from Laisha's knowledge because the official page could not be opened or was not found during research (web search quota exhausted); confirm against the body's current notification before relying on it. These schools train most official statisticians of francophone Africa. The ENSAE page fetched returned a search page, not the exam notice.
Official source: https://www.ensae.fr/
Original questions written to this exam's published syllabus and pattern. Not past papers.
1. Among persons aged 23 to 62 in a census, 9,600 report their age, of whom 2,400 report an age ending in 0 or 5. What is Whipple's index?
D. 125
Whipple's index = (number reporting ages ending in 0 or 5 × 5)/(total aged 23-62) × 100 = 2,400 × 5/9,600 × 100 = 125. The index runs from 100 (no preference for 0 and 5) to 500 (every age ends in 0 or 5); 125 shows moderate heaping. 25 omits the factor 5.
Demography & Vital Statistics · Sources of demographic data: census, civil registration and sample registration
2. Two items have base-period expenditure shares of 0.4 and 0.6 and price relatives of 1.10 and 1.30. What is the Laspeyres price index computed as a weighted mean of relatives?
B. 122.00
With base expenditure shares as weights, the weighted arithmetic mean of relatives equals the aggregative Laspeyres: 0.4 x 1.10 + 0.6 x 1.30 = 0.44 + 0.78 = 1.22, so 122. 120 is the unweighted mean; 119.58 is the unweighted geometric mean sqrt(1.10 x 1.30) x 100.
Index Numbers, National Accounts & Agricultural Economic Statistics · Index numbers: Laspeyres, Paasche, Fisher and Marshall-Edgeworth
3. What does post-neonatal mortality mainly reflect?
C. Infections, nutrition and the household environment
Deaths from 28 days to one year are dominated by infectious disease, malnutrition and environmental conditions; neonatal deaths reflect pregnancy, delivery and newborn care.
Demography & Vital Statistics · Measures of mortality: crude, age-specific and standardised death rates; infant mortality
4. Barter terms of trade of agriculture have improved by 15%. Which conclusion is justified without further data?
D. Farm prices rose relative to prices farmers pay
The barter index is purely a price ratio. Income depends also on quantities sold and costs, and productivity on output per unit of input; a drought could cut output and income while prices, and so the terms of trade, rise.
Index Numbers, National Accounts & Agricultural Economic Statistics · Parity index and terms of trade between agriculture and non-agriculture
5. A population grows from 100 million to 150 million in 10 years. What is the exponential growth rate?
B. 4.05% per year
r = ln(150/100)/10 = ln 1.5/10 = 4.05% per year. 4.14% is the geometric (annually compounded) rate; 5% is the arithmetic rate.
Demography & Vital Statistics · Population growth models: exponential and logistic curves
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