The data here shows an hypothetical age distribution of the population of a town in Nigeria. Sex Age in years 10 and below 11-14 15-3 36 - 64 65 and above M...

Each column must add up to its total, so the missing figures are found by subtraction.

(a)
\(X=\) the 11-14 total \(=2{,}275+2{,}725=5{,}000\).
\(Y=\) males aged 36-64 \(=7{,}500-4{,}265=3{,}235\).
\(Z=\) females aged 65 and above \(=6{,}000-3{,}250=2{,}750\).

(b) Total population \(=4{,}000+5{,}000+2{,}500+7{,}500+6{,}000=25{,}000\).

(c) Aged 14 and below: males \(=1{,}350+2{,}275=3{,}625\); females \(=2{,}650+2{,}725=5{,}375\). Difference \(=5{,}375-3{,}625=1{,}750\) (there are 1,750 more females).

(d) Percentage aged 14 and below \(=\dfrac{3{,}625+5{,}375}{25{,}000}\times100=\dfrac{9{,}000}{25{,}000}\times100=36\%\).

(e) Dependants are those aged 14 and below (9,000) and 65 and above (6,000), a total of 15,000; the working group (15-64) is \(2{,}500+7{,}500=10{,}000\). Dependency ratio \(=\dfrac{15{,}000}{10{,}000}=1.5\) (that is 150%, or 3 dependants to every 2 workers).