Answer:
a) 69.5 b)72.1 c)74.7
Step-by-step explanation:
a)Someone born in 1950 has life expectancy=68.2 yrs while 1970=70.8 yrs
to find life expectancy of someone born in 1960 we can interpolate to find the results like this:
(68.2+70.8)/2 =69.5 because 1960 is exactly in between 1950 and 1970
Now we can see the trend like this :
68.2,69.5,70.8 and common difference is 1.3
b) adding 1.3 to 70.8 we can get life expectancy for someone born i 1980 and that is 72.1
c) adding two times 1.3 life expectancy of someone born in 2000 is 74.7 as year gap is 2
Generally it is said that interpolation is more accurate and extrapolation can have errors but in our present case i'm more confident about b and c as the series is simple but it too depends on a to find the accurate common difference so if there is some errror in a we too have error chances in b and c so they are interrelated.
