What is seemingly a straightforward question has been driving me crazy for a good while now.. Calculate 2.5q75.75 using the method of Uniform Distribution of Deaths. Basis: Mortality PMA92C20 I understand the method used in the mark scheme but I used the method of interpolating lx values (which I have previously used for other questions) as follows: 2.5q75.75 = 1 - (0.25p75.75 * 2p76 * 0.25p78) =1*(l76/l75.5)*(l78/l76)*(l78.25/l78) Simplifying gives: =1-(l78.25/l75.25) using the above mortality basis and interpolating: l78.25 = 0.25*l79 +0.75*l78 = 0.25*7298.223 + 0.75*7615.818 = 7536.41925 l75.25 = 0.25*8168.798 +0.75*8405.160 = 8346.0695 Therefore: 2.5q75.75 = 1 - (7536.51295/8346.0695) = 0.097 as opposed to 0.08404 in the answers? I'm not sure what it is that I'm missing? Probably something simple but any help will be much appreciated!
Be careful of careless mistakes. Yes, I also made one in this thread. The general methodology is correct, but this specific step is what's missing, as your l75.75 somehow changed to l75.25 (and the calculation of that is consistent with l75.25), so your answer is effectively finding 3q75.25 instead.