Research and statistics case
February 13th, 2023
Chicken Delight claims that 90 percent of its orders are delivered
within 10 minutes of the time the order is placed. A sample of 100 orders
revealed that 82 were delivered within the promised time. At the 10
significance level, can we conclude that less than 90 percent of the orders
are delivered in less than 10 minutes?
The MacBurger restaurant chain claims that the waiting time of customers
for service is normally distributed, with a mean of 3 minutes and a standard
deviation of 1 minute. The quality-assurance department found in a sample of
50 customers at the Warren Road MacBurger that the mean waiting time was
2.75 minutes. At the .05 significance level, can we conclude that the mean
waiting time is less than 3 minutes?
