Exam 18: Statistical Applications in Quality Management

TABLE 18-8 Recently,a university switched to a new type of computer-based registration.The registrar is concerned with the amount of time students are spending on the computer registering under the new system.She decides to randomly select 8 students on each of the 12 days of the registration and determine the time each spends on the computer registering.The range,mean,and standard deviation of the times required to register are in the table that follows. -Referring to Table 18-8,an chart is to be used for the time required to register.The lower control limit for this data set is ________,while the upper control limit is ________.

TABLE 18-9 The manufacturer of canned food constructed control charts and analyzed several quality characteristics.One characteristic of interest is the weight of the filled cans.The lower specification limit for weight is 2.95 pounds.The table below provides the range and mean of the weights of five cans tested every fifteen minutes during a day's production. -Referring to Table 18-9,an R chart is to be constructed for the weight.The upper control limit for this data set is ________.

TABLE 18-2 A political pollster randomly selects a sample of 100 voters each day for 8 successive days and asks how many will vote for the incumbent.The pollster wishes to construct a p chart to see if the percentage favoring the incumbent candidate is too erratic. -Referring to Table 18-2,what is the numerical value of the center line for the p chart?

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -True or False: The p chart is a control chart used for monitoring the proportion of items that meet given specifications.

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -Referring to Table 18-4,suppose the supervisor constructs an R chart to see if the variability in collection times is in-control.What are the lower and upper control limits for this R chart?

TABLE 18-5 A manufacturer of computer disks took samples of 240 disks on 15 consecutive days.The number of disks with bad sectors was determined for each of these samples.The results are in the table that follows. -Referring to Table 18-5,a p control chart is to be made for these data.The estimate of the standard error of the proportion of disks with bad sectors is ________.

Maintaining the gains that have been made with a revised process in the long term by avoiding potential problems that can occur when a process is changed involves which part of the DMAIC process?

TABLE 18-10 Below is the number of defective items from a production line over twenty consecutive morning shifts. -True or False: Referring to Table 18-10,the c chart suggests that the special cause of variation must be incorporated into the process to become part of the permanent ongoing process.

Which of the following best measures the ability of a process to consistently meet specified customer-driven requirements?

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -Referring to Table 18-4,suppose the supervisor constructs an chart to see if the process is in-control.What are the lower and upper control limits of this chart?