# Stats Question

1. Nov 30, 2008

### Paulo2014

1. The problem statement, all variables and given/known data

(a) Shedz buys its trays in pallets by the container load. As each container arrives, n trays are examined
to assess whether or not the load of trays is of acceptable quality. The load is accepted if there is no
more than one defective tray in the sample.
(i) For two successive loads, 1% and 2% of the trays were defective, respectively.
If n = 50 for each load, find the probability that at least one of these two loads was accepted.
(ii) If 1% of the trays are defective in a load, find the largest value of n which ensures there is
approximately a 94% chance of the load being accepted.
(b) Each pallet consists of 180 trays stacked in 30 levels, with six trays arranged as a 3 by 2 rectangle at
each level.
(i) Describe how cluster sampling could be used to select 24 trays from a container load of 20
pallets.
(ii) Give one advantage and one disadvantage of using cluster sampling in this situation,
compared with simple random sampling.

2. Relevant equations

3. The attempt at a solution

I'm completly stuck....
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution