1. A factory is testing a new machine on its production line that is intended to improve efficiency. Management randomly
selects 12 employees and measures the number of products they complete in one hour when using the new machine. Below
are the results.
Employee 1 2 3 4 5 6 7 8 9 10 11 12
# units 72 68 74 78 75 79 71 69 82 71 73 80
(a) Estimate at the 95% confidence level the average number of units an employee can produce in one hour using the
new machine.
(b) The manufacturer of the machine claims the typical efficiency for a factory worker should be 78 units per hour. What
does the interval suggest about the manufacturer’s claim