Assume that each sample is obtained by randomly selecting values from a population with a normal distribution.
A container of car antifreeze is supposed to hold 3785 mL of the liquid. Realizing that fluctuations are inevitable, the quality control manager wants to be quite sure that the standard deviation is less than 30 mL. Otherwise, some containers would overflow while others would not have enough of the coolant. She randomly selects a sample, with the results given here. Use these sample results to construct the 99% confidence interval for the true value of cr. Does this confidence interval suggest that the fluctuations are at an acceptable level?

3761 3861 3769 3772 3675 3861| n=18 3888 3819 3788 3800 3720 3748 3787.0 3753 3821 3811 3740 3740 3839] s=55.4