Hi, Im new to the site so apologies if I haven't posted the question correctly.

But here goes, I have been given this question as an example to complete and truth be told I don't understand the process for working it out. If anyone could help me out it would be greatly appreciated.

In a large retail furniture outlet, customers walk round a show area and then order their selection at a service point. The selected goods are then sent from the warehouse to the dispatch point by means of a lift. This lift is operated in such a way that a single customer order is carried. From past records it is known that the weight of a randomly selected customer order is Normally distributed with a mean of 200Kg and a standard deviation of 45Kg.

A customer’s order is selected at random. What is the probability that the weight is
• Less than 177Kg
• Between 160 and 220 Kg

What is the probability that the total weight of 10 randomly selected orders is greater than 2300Kg?


Thanks