A store sells a large number of packets of resistors. They are packed in $3$ packet sizes: $10$,$20$ and $30$ resistors per packet and are sold int the ratio $1:3:2$ respectively. A random sample of $3$ packets is taken from the shelve.
(i) List the sample space.
(ii) Determine the sampling distribution of the mean and median.
What i tried
(i)The sample space represents all the possible outcomes of the resistors being chosen which in this case are all the possible combinations of the resistors per packet chosen. But i dont quite get what has the ration $1:3:2$ has go anything to do with this . Could anyone pleas explain. Thanks
(ii) The mean is $(10*1+20*3+30*2)/(1+3+2)$ to get the average number of resistors per packet. The median is the $50th$ percentile which is $20$ resistors per packet. Am i correct. Could anyone explain. Thanks