Before Any Order Is Shipped, Inspectors at Alvarez Manufacturing Test

Multiple Choice

Before any order is shipped, inspectors at Alvarez Manufacturing test a sample of finished units for breaking strength.You select a simple random sample of units from a recently completed order and find that the sample average breaking strength is 814 pounds.From the sample selected, you construct a 95% confidence interval estimate of the average breaking strength you could expect to find if all the units in the order were tested.The interval turns out to be 814 ± 7.5 lbs.How would you interpret your result?

A) Approximately 95% of the units in the order will have a breaking strength of between 806.5 lbs.and 821.5 lbs.
B) Approximately 95% of the units in the sample have a breaking strength of between 806.5 lbs.and 821.5 lbs.
C) Approximately 95% of the units in the population will have a breaking strength of between 806.5 and 821.5 lbs.
D) We can be 95% confident that all the units in the order have a breaking strength of between 806.5 lbs.and 821.5 lbs.
E) If we were to repeat this estimating procedure a large number of times, approximately 95% of the intervals we construct would contain the actual order average breaking strength.