Life expectancy

[rad6210]

Given e93 = 2.4, e94 = 2.3, and e95 = 2.2. Out of 4,400 alive at age 93, how many will survive to age 95?

The answer is given as 2,300. I know the life expectancy at age x: lx = Px(1 + ex+1) , with px = (lx + 1) / lx, which is the survival rate at age x. But I'm getting confused ... is it saying l93 = 4400 and asking for P95?

 

[mmm4444bot]

I do not understand the notation.

Can you define the symbolism used, or can you provide an on-line reference?

It seems to me that (1 + ex + 1) = (ex + 2), but I'm not sure what the symbolism ex represents.

 

[rad6210]

Oh I'm sorry when I copied it over the x's and numbers were subscripts but I can't get them to stay that way once it posts ... but the 93, 94, and 95's should be subscripts as well as the x's and x+1's ... if that helps at all. And I'm not really sure what the ex by itself means either, which is probably why I'm getting confused, I just know its part of the life expectancy function

 

[tkhunny]

Given e93 = 2.4, e94 = 2.3, and e95 = 2.2. Out of 4,400 alive at age 93, how many will survive to age 95?

The answer is given as 2,300. I know the life expectancy at age x: lx = Px(1 + ex+1) , with px = (lx + 1) / lx, which is the survival rate at age x. But I'm getting confused ... is it saying l93 = 4400 and asking for P95?

e93 = p93 + 2p93 + 3P93 + other stuff = p93 + p93*p94 + p93*p94*p95 + other stuff

e94 = p94 + 2p94 + other stuff = p94 + p94*p95 + other stuff

e95 = p95 + other stuff

Can you decode all that?