This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: ISOM 111 L7-L8, Fall 2010 1 Homework 4 Due: Friday, Nov 12, 4:00pm Submit to the “ISOM 111 L7-L8 Homework Collection Box” outside Room 4351 I . When a pizza restaurant’s delivery process is operating effectively, pizzas are delivered in an average of 45 minutes with a standard deviation of 6 minutes. To monitor its delivery process, the restaurant randomly selects five pizzas each night and records their delivery times. (a). For the sake of argument, assume that the population of all delivery times on a given evening is normally distributed with a mean of μ = 45 minutes and a standard deviation of σ = 6 minutes. (That is, we assume that the delivery process is operating effectively.) (1). Describe the shape of the population of all possible sample means. How do you know what the shape is? (2). Find the mean of the population of all possible sample means. (3). Find the standard deviation of the population of all possible sample means. (4). Calculate an interval containing 99.7 percent of all possible sample means. (b). Suppose that the mean of the five sampled delivery times on a particular evening is ¯ x = 55 minutes. Using the interval that you calculated in (a.4), what would you conclude about whether the restaurant’s delivery process is operating effectively? Why? II . In an article in the Journal of Marketing , Bayus studied the differences between “early replacement buyers” and “late replacement buyers” in making consumer durable good replacement purchases. Early replacement buyers are consumers who replace a product during the early part of its lifetime, while late replacement buyers make replacement purchases late in the product’s...
View Full Document
This note was uploaded on 12/04/2010 for the course ISOM ISOM111 taught by Professor Anthonychan during the Fall '09 term at HKUST.
- Fall '09