The table below shows the quantity of yams (in kg) produced by four yam producing states in Nigeria between 1995 and 1998; Quantity of yams in kilograms pro...

Answer Details

First set the data out clearly. Reading the table by year-column, the quantities (in kg) are:

(a) Total quantity of yams produced by the four states, 1995 to 1998

Add the four yearly totals: \[2{,}100{,}000 + 2{,}200{,}000 + 2{,}400{,}000 + 2{,}500{,}000 = 9{,}200{,}000\ \text{kg}.\] The total quantity produced during the period is 9,200,000 kg.

(b) Pie chart of the 1998 output

The 1998 total is \(600{,}000 + 700{,}000 + 800{,}000 + 400{,}000 = 2{,}500{,}000\) kg. Each state's angle is found from \[\theta = \frac{\text{state output}}{\text{total}} \times 360^{\circ}.\]

To draw it: construct a circle of convenient radius, mark a starting radius (12 o'clock), and use a protractor to mark off the angles in order, largest to smallest. Shade each sector differently, label it with the state and its value or percentage, and add a title and key.

(c) Two advantages of a pie chart

1. It shows clearly the proportion or share that each part contributes to the whole.
2. It gives an easy visual comparison between the sectors, so the largest and smallest producers are seen at a glance.