The number of television sets produced from an assembly line each day is known to have a standard deviation of 17.4 sets per day. The production line averaged 452.3 sets per day for 20 randomly selected days. Which of the following represents a 95% confidence interval for the population mean number of sets per hour?
A)	452.3 9.4
B)	452.3 11.3
C)	452.3 13.8
D)	452.3 7.63
Answer:D
The number of television sets produced from an assembly line each day is known to have a standard deviation of 17.4 sets per day. The production line averaged 452.3 sets per day for 20 randomly selected days. Which of the following represents a 95% confidence interval for the population mean number of sets per hour?
A)	452.3 9.4 B)	452.3 11.3 C)	452.3 13.8 D)	452.3 7.63