(i) State the principle of correspondence as it relates to mortality investigations. [1] Two small countries conduct population censuses on an annual basis. Country A records its population on 1 February every year based on an age definition of age last birthday. Country B records its population on every 1 August using a definition of age nearest birthday. Each country records deaths as they happen based on age next birthday. Below are some data from the last few years. Age last birthday 44 45 46 Country A Population Population Population 1 February 2011 1 February 2012 1 February 2013 382,000 394,000 374,000 381,000 354,000 372,000 401,000 385,000 375,000 Country B Age nearest Population Population birthday 1 August 2011 44 382,000 1 August 2012 394,000 Population 1 August 2013 401,000 45 374,000 381,000 385,000 46 354,000 372,000 375,000 In the combined lands of Countries A and B in the calendar year 2012 there were 4,800 deaths of those aged 46 next birthday and 4,500 deaths of those aged 45 next birthday. The two countries decide to form an economic union, after which it will be mandatory to offer the same rates for life insurance to residents of each country. (ii) Estimate the death rate at age 45 years last birthday for the two countries combined. (iii) Explain the exact age to which your estimate relates. [6] [1] [Total 8]