A routine check is to be conducted on a filling machine for "200g" yoghurt containers.For this machine, the standard deviation of the weight poured into each container is known to be 12g.In the checking procedure, a random sample of 50 containers is examined.The contents are found to have a mean weight of 207g.

Part A

Find thefull widthof a 99% confidence interval for the true mean contents. Give your answer to 2 decimal places in the form x.xx

Answer:

Part B

What is thelower limitof this confidence interval?Give your answer to two decimal places in the form xxx.xx

:

could you explain these questions?