# Question: in order to determine the average weight of large parcels...

###### Question details

In order to determine the average weight of large parcels at a post office, a sample of 31 parcels was weighed. The average weight was found to be 5.7 kg with a standard deviation of 6.5 kg. Determine a 90% confidence interval for the mean weight of large parcels. State the lower limit only (in kg) correct to two decimal places. Use z table, not cas calculator.