QA 233 (Basic Business Statistics)

Practice Problems V - Chapter 5


Hello QA 233 students! The following problems require you to use material from 'Discrete Probability Distributions' (slide set 5 and chapter 5 in the ASW textbook). I have also posted the solutions on the Virtual Classroom web page. Have a good day.


Pillar Foods, Inc. produces Choco-Poofies, a breakfast cereal popular with young children. They currently produce ten ounce, twenty ounce, and three pound (thirty-six ounce economy size) boxes of this cereal. After a slurry of the ingredients is mixed, it is extruded through a star-shaped mold, cut into quarter-inch wide pieces, and baked until crunchy. Every production employee has the capability of bringing production to an immediate stop if he/she observes a problem with the process. Once the baking process is complete, the final product is brought by conveyor belt into machines that funnel the product into boxes. A ticket with a point value of 1, 2, 3, 4, or 5 (redeemable for a plastic giraffe, a plastic elephant, a plastic hippopotamus, a plastic three-toed sloth, or a plastic hyena once a certain number of points is accumulated) is then dropped into the box, and the box is sealed.

  1. Suppose that the average number of times the production process is stopped by an employee throughout a single shift (eight hours) is 3.5. What is the probability that the process will not be stopped during a one-hour period? What is the probability that the process will be stopped at least twice during a one-hour period? - QA 233 Students - only identify what type of distribution would describe the random variable in this problem!

 

  1. If tickets of the various point values (1, 2, 3, 4, 5) are distributed throughout the boxes evenly, what is the probability that a randomly selected box will include a ticket with a point value of at least four? Under these conditions, what is the probability that a randomly selected box will include a ticket with a point value of no more than two?

 

  1. Again assume the conditions outlined in problem 2 (tickets of each point value are equally likely) are true. If you randomly select twelve boxes of Choco-Poofies, what is the probability that at least three of the boxes will contain a five-point ticket? What is the probability that none of the boxes will contain a one-point ticket?

 

  1. Each day Pillar Foods randomly selects ten of their 1250 production employees to perform quality control inspections throughout the production process. In order to cover all quality control-related tasks, at least eight of the ten randomly selected employees must be at work on that day. If the probability that any worker will call in sick on a given day is 0.05, what is the probability Pillar Foods will not have enough employees from the ten who have been randomly selected to perform their quality control tasks (i.e., that at least two of the selected workers will call in sick on a given day)?

 


 

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