The exercise reads:
In the storage of a stock of $100Kg$ flour bags, a random error $X$ is committed whose density function is of the form $f(x)=k(1-x^2)$, if $-1<x<1$ and $f(x)=0$, otherwise.
- $a)$ Calculate the probability that a sack of flour will pass from $99,5Kg$.
- $b)$ What percentage of sacks will have a weight between $99,8$ and $100,2Kg$?
My question is, the relationship between the error and the $100Kg$. Are we talking about a margin of error of $+1 Kg$ and $-1Kg$ respectively? That is:
In the part $ a) $ I must calculate $ P (X< -0.5) $ and in the part $ b) $ $ P (-0.2 <X <0.2) $?
Thank you very much.