Theory question 202
Statistical Maps and DiagramsThe table below shows the direct premium income of non-life insurance business for Nigeria in a particular year. Use the data to answer the questions that follow:
Fire: value ₦24,532,000, percentage 12.1
Accident: ₦13,770,000, 6.8
Motor: ₦94,442,000, ?
Marine: ₦49,536,000, 24.5
Miscellaneous: ₦20,040,000, ?
Total: ₦202,320,000, 100
(a) Calculate the missing percentages for motor and miscellaneous premium incomes. (b)(i) Construct a percentage bar graph to illustrate the above statistics. (ii) State two disadvantages of a percentage bar graph. (c) Suggest an alternative method of representing the statistics.
Show the model answer
(a) Motor = 94,442,000 ÷ 202,320,000 × 100 = 46.7%; Miscellaneous = 20,040,000 ÷ 202,320,000 × 100 = 9.9% (check: 12.1 + 6.8 + 46.7 + 24.5 + 9.9 = 100).
(b)(i) One bar of suitable length (e.g. 10 cm = 100%) divided into segments: fire 1.21 cm, accident 0.68 cm, motor 4.67 cm, marine 2.45 cm, miscellaneous 0.99 cm; each shaded differently with a key, title and scale.
(ii) Actual values cannot be read from it; percentages must first be calculated, which takes time and can introduce errors; very small parts are hard to show; difficult to compare with other years with different totals.
(c) Pie chart (or divided circle), simple bar graph, or divided rectangle.
Show the formula and working, and make sure the percentages add to 100.