196 



ESSAY ON PROBABILITIES. 



The preceding table contains the values of annuities 

 upon two lives, for all ages which are multiples of 5. 

 Thus, for the ages 25 and 40, look to that part of the 

 table in which the ages differ by 15 years, and there, 

 opposite to 25 40, will be found, under 4 per cent., 

 132 in the Carlisle table and 107 in the Northampton. 

 That is, money making 4 per cent., an annuity of 10/., 

 which is to continue as long as lives of 25 and 40 are 

 both in being, is worth something between 1 311. 10s. Od. 

 and 132/. 10s. Od. according to the Carlisle tables, and 

 something between 1067. 10s, Od. and 107/. 10s. Od. 

 according to the Northampton tables. 



When the two required lives have ages which do 

 not end with the figures or 5, proceed as follows: Let 

 the value of annuity be required on joint lives of 38 

 and 47, (Carlisle tables at 3 per cent.). First take 35 and 

 45, and 40 and 45, and between the corresponding annuities 

 insert such a mean as would represent 38 and 45 upon the 

 supposition uniformly diminishing values. Then be- 

 tween 35 and 50 and 40 and 50 insert such a mean 

 as answers to 38 and 50. Having then 38 and 45 

 and 38 and 50, find such a mean as answers to 38 and 

 47. This process, which will be intelligible to a 

 reader who has practised similar ones before, will only 



