The expected weight is the same thing as the mean weight.Originally Posted bynorivea

The mean of the sum of two random variables is the sum of their means

so in this case it is .

The variance of the sum of two independent random variables is the sumb) the variance of a filled contained of raisins.

of the variances. The variance is the square of the standard deviation so

in this case the required variance is

This is the square root of the variance so isc) the standard deviation of a filled container of raisins.

RonL