MATH 221 Week 5 Quiz

1. Question: Let x represent the number of cars in a parking lot. This would be considered what type of variable: 2. Question: Let x represent the height of corn in Oklahoma. This would be considered what type of variable: 3. Question: If you created the probability distribution for these data, what would be the probability of 40-49? 4. Question: Consider the following table.Find the mean of this variable. 5. Question: Consider the following table. Find the variance of this variable. 6. Question: Consider the following table.Find the standard deviation of this variable. 7. Question: The standard deviation of samples from supplier A is 0.4582, while the standard deviation of samples from supplier B is 0.3358. Which supplier would you be likely to choose based on these data and why? 8. Question: Ten frequent gamers are randomly selected. The random variable represents the number of frequent gamers who play video games on their smartphones. For this to be a binomial experiment, what assumption needs to be made? 9. Question: A survey found that 31% of all teens buy soda (pop) at least once each week. Seven teens are randomly selected. The random variable represents the number of teens who buy soda (pop) at least once each week. What is the value of n? 10. Question: You randomly select eight US adults. Find the probability that the number of US adults who have little confidence in their cars is (1) exactly three and then find the probability that it is (2) more than 6. 11. Question: Say a business found that 45% of customers in Detroit, MI prefer green sweaters. The company chooses 8 customers in Austin, TX and asks them if they prefer green sweaters. What assumption must be made for this study to follow the probabilities of a binomial experiment? 12. Question: Seven baseballs are randomly selected from the production line to see if their stitching is straight. Over time, the company has found that 89.4% of all their baseballs have straight stitching. If exactly five of the seven have straight stitching, should the company stop the production line? 13. Question: A bottling company puts 16 ounces of water bottle in each bottle. The company has determined that 94% of bottles have the correct amount. Which of the following describes a binomial experiment that would determine the probability that a case of 12 cans has all cans that are properly filled? 14. Question: A supplier must create metal rods that are 16.4 inches long to fit into the next step of production. Can a binomial experiment be used to determine the probability that the rods are too long, too short, or about right? 15. Question: In a box of 12 pens, there is one that does not work. Employees take pens as needed. The pens are not returned, once taken. You are the 5th employee to take a pen. Is this a binomial experiment? 16. Question: Eighty-two percent of employees make judgements about their co-workers based on the cleanliness of their desk. You randomly select 7 employees and ask them if they judge co-workers based on this criterion. The random variable is the number of employees who judge their co-workers by cleanliness. Which outcomes of this binomial distribution would be considered unusual? 17. Question: Eighty-one percent of products come off the line within product specifications. Your quality control department selects 15 products randomly from the line each hour. Looking at the binomial distribution, if fewer than how many are within specifications would require that the production line be shut down (unusual) and repaired? 18. Question: The probability of a potential employee passing a drug test is 90%. If you selected 11 potential employees and gave them a drug test, how many would you expect to pass the test? 19. Question: The probability of a potential employee passing a training course is 86%. If you selected 15 potential employees and gave them the training course, what is the probability that 11 or less will pass the test? 20. Question: Off the production line, there is a 4.6% chance that a candle is defective. If the company selected 50 candles off the line, what is the standard deviation of the number of defective candles in the group?