Afarm-equipment manufacturer wants to compare the average daily downtime (in minutes) for two sheet-metal stamping machines located in two different factories. investigation of company records for 100 randomly selected days on each of the two machines gave the following 95% confidence interval for the difference between average daily downtime in factories a and b: (1.968, 2.674).
a. this means: 95% of the time, the difference in daily average downtime between the factories is between 1.968 minutes and 2.674 minutes.
b. there is a 95% chance that the difference in daily average downtime is between 1.968 minutes and 2.674 minutes. c. we are 95% certain that the average daily downtime between factories is the same.
d. we are 95% certain that the average daily downtime differs between the two factories.
e. factory a experiences downtime about twice as often as factory b.