chapter 3 OPSM

c

70. Consider a production process that produces tires. A quality engineer has taken 15 samples, each containing 200 tires. The total number of defective tires over the 15 samples is 340. The sample standard deviation is a. 0.005 b. 0.011 c. 0.022 d. 0.028

d

71. Consider a production process that produces tires. A quality engineer has taken 15 samples, each containing 200 tires. The total number of defective tires over the 15 samples is 340. The UCL for the control chart constructed using two sigma is a. 0.025 b. 0.094 c. 0.122 d. 0.154

b

74. Easy Tax is a service company that prepares tax returns. An outside auditor has examined 20 samples each containing one completed tax return. The total number of defects observed over the 20 samples is 200. The centerline for the control chart constructed is a. 5 b. 10 c. 15 d. 20

b

75. Easy Tax is a service company that prepares tax returns. An outside auditor has examined 20 samples each containing one completed tax return. The total number of defects observed over the 20 samples is 200. The standard deviation for the control chart is a. 2.2 b. 3.2 c. 3.9 d. 4.5

a

76. Easy Tax is a service company that prepares tax returns. An outside auditor has examined 20 samples each containing one completed tax return. The total number of defects observed over the 20 samples is 200. The UCL for the control chart constructed using three sigma is a. 19.6 b. 26.7 c. 33.5 d. 50.0

c

79. Marble Inc. makes countertops from a variety of high-end materials. To monitor the quality of its production processes the company randomly selects one countertop and counts the number of blemishes. The results for ten samples are shown below: Sample No. 1 2 3 4 5 6 7 8 9 10 No. of Blemishes 17 19 15 18 16 14 15 16 15 15 Given the sample information above, the standard deviation of the number of defects for this process would be a. 16 b. 10 c. 4 d. 0

d

81. Marble Inc. makes countertops from a variety of high-end materials. To monitor the quality of its production processes the company randomly selects one countertop and counts the number of blemishes. The results for ten samples are shown below: Sample No. 1 2 3 4 5 6 7 8 9 10 No. of Blemishes 17 19 15 18 16 14 15 16 15 15 Given the sample information above, the LCL using sigma = 3 for this process would be a. 12 b. 8 c. 4 d. 0

c

82. A control chart that reflects the amount of variation, or spread, present within each sample is known as a(n) a. p-chart b. c-chart c. R-chart d. x chart

a

83. Which of the following control charts is used to control the variation within samples? a. x chart b. R chart c. c-chart d. p-chart

d

85. Which of the following charts are frequently used together to monitor and control quality? a. p and x b. R and p c. c and R d. R and x

d

A process is generally considered to be in control when a. there are no sample points outside the control limits b. most points are near the center line, without many being close to the control limits c. sample points are randomly distributed equally above and below the center line d. All of these answer choices are correct

a

XYZ manufacturing has received an order to produce a rod 5 inches in diameter + .04 inch. In sample runs, the machine tool that will be making the rod has been able to produce rods with a mean diameter of 4.99 inches and a standard deviation of 0.011 inch. The process capability index for this process is a. 0.91 b. 1.51 c. -0.91 d. -1.51

c

108. XYZ manufacturing has received an order to produce a rod 5 inches in diameter + .04 inch. In sample runs, the machine tool that will be making the rod has been able to produce rods with a mean diameter of 4.99 inches and a standard deviation of 0.011 inch. Which of the following statements is true? a. The process is capable of meeting design spec but is off-center. b. The process is capable of meeting design specs and is on-center. c. The process in incapable of meeting design specs.

b

40. If a sample point plotted on a control chart is outside the control limits a. the evidence indicates the process is in control. b. the evidence indicates the process is out of control. c. the evidence is inconclusive. d. None of these answer choices is correct.

d

41. Which of the following could be responsible for variability that is special cause (nonrandom)? a. Broken machinery. b. Defective parts and materials. c. Operator error. d. All these answer choices are correct.

c

52. The basic purpose of control charts include(s) a. establishing control limits for a process. b. monitoring the process to indicate when it is out of control. c. both establishing control limits for a process and monitoring the process to indicate when it is out of control are basic purposes. d. None of these answer choices is correct

c

53. The formulas for determining the upper and lower control limits are based on the number of standard deviations, z, from the process average. Management usually selects a z value of _______. a. one b. two c. three d. six

c

54. When a control chart is first developed, if the process is found to be out of control, a. the control chart can be utilized. b. the control chart should not be utilized until more samples are taken, c. the process should be examined and corrections made before a new control chart is constructed. d. the process should be replaced by a new process.

a

88. Pizazz manufactures a 5.0 oz. energy drink of the same name. Because the cans are so small, consumers are concerned that they are not receiving the full 5 ounces in each can. A quality engineer at the company is charged with analyzing the filling process and ensuring accurate readings. On 15 different occasions over the past month, she has taken a sample of 6 energy drinks off the production line and recorded their weight. If the sum of the sample means is 80.20 ounces and the sum of the sample ranges is 12.68 ounces, the UCL for an R-chart of this process would be a. 0.0 b. 1.0 c. 1.7 d. 2.4

c

89. Pizazz manufactures a 5.0 oz. energy drink of the same name. Because the cans are so small, consumers are concerned that they are not receiving the full 5 ounces in each can. A quality engineer at the company is charged with analyzing the filling process and ensuring accurate readings. On 15 different occasions over the past month, she has taken a sample of 6 energy drinks off the production line and recorded their weight. If the sum of the sample means is 80.20 ounces and the sum of the sample ranges is 12.68 ounces, the centerline for an X-bar chart of this process would be a. 4.75 b. 5.00 c. 5.35 d. 5.69

a

A company produces a product which is designed to weigh 10 oz., with a tolerance of + 0.5 oz. The process produces products with an average weight of 9.95 oz. and a standard deviation of 0.10 oz. The process capability index for this process is a. 1.50 b. -1.50 c. 1.83 d. -1.83

c

94. Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an X-bar chart from this data, the 3-sigma LCL would be Samples Observations (mins) 1 2 3 4 1 5.4 4.6 6.0 1.5 2 2.8 3.9 4.6 5.4 3 5.7 3.1 2.8 2.2 4 4.1 4.3 5.3 2.8 5 2.9 1.3 4.1 3.0 6 3.3 4.3 4.2 3.9 a. 0.00 b. 1.00 c. 1.76 d. 2.82

b

95. Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an R-chart from this data, the centerline would be Samples Observations (mins) 1 2 3 4 1 5.4 4.6 6.0 1.5 2 2.8 3.9 4.6 5.4 3 5.7 3.1 2.8 2.2 4 4.1 4.3 5.3 2.8 5 2.9 1.3 4.1 3.0 6 3.3 4.3 4.2 3.9 a. 1.00 b. 2.82 c. 3.54 d. 3.81

a

A company produces a product which is designed to weigh 10 oz., with a tolerance of + 0.5 oz. The process produces products with an average weight of 9.95 oz. and a standard deviation of 0.10 oz. According to the process capability index a. the process mean is off center having shifted to the right b. the process mean is off center having shifted to the left c. the process mean is centered on the design target d. None of these answer choices is correct.

d

A company produces a product which is designed to weigh 10 oz., with a tolerance of + 0.5 oz. The process produces products with an average weight of 9.95 oz. and a standard deviation of 0.10 oz. According to the process capability ratio is the process capable of meeting design specifications? a. No, the process capability ratio is less than 1.0 b. Yes, the process capability ratio is less than 1.0 c. No, the process capability ratio is greater than 1.0 d. Yes, the process capability ratio is greater than 1.0

c

If a sample of 40 units of output found 500 defects, then the center line for monitoring the average number of defects per unit of output would be a. = 40 b. = 0.08 c. = 12.5 d. = 20,000

b

In general, a process is considered to be in control for all the following conditions except a. no points are outside the control limits b. all points are above the centerline c. the points are randomly distributed following a normal population d. no pattern exists in the plotted points

c

a. 90. Pizazz manufactures a 5.0 oz. energy drink of the same name. Because the cans are so small, consumers are concerned that they are not receiving the full 5 ounces in each can. A quality engineer at the company is charged with analyzing the filling process and ensuring accurate readings. On 15 different occasions over the past month, she has taken a sample of 6energy drinks off the production line and recorded their weight. If the sum of the sample means is 80.20 ounces and the sum of the sample ranges is 12.68 ounces, the UCL for an X-bar chart of this process would be a. 5.00 b. 5.35 c. 5.76 d. 6.45

b

A company randomly selects 100 light bulbs every day for 40 days from its production process. If 600 defective light bulbs are found in the sampled bulbs then the 3-sigma lower control limit would be a. 0.0357 b. 0.0429 c. 0.1500 d. 0.1857

b

A control chart that uses the actual number of defects per item to monitor a process is known as a a. p-chart b. c-chart c. R-chart d. -chart

c

Which of the following control charts are based on sample sizes as small as one? a. x b. R c. c d. p

d

Which of the following control charts are often based on sample sizes equal to or larger than one hundred? a. x b. R c. c d. p

c

Which of the following control charts is based on the number of defects within a sample? a. x b. R c. c d. p

d

Which of the following control charts is used to monitor the percent of defective items within a sample? a. x b. R c. c d. p

a

a. 102. A company produces a product which is designed to weigh 10 oz., with a tolerance of + 0.5 oz. The process produces products with an average weight of 9.95 oz. and a standard deviation of 0.10 oz. The process capability ratio for this process is a. 1.67 b. 0 c. 0.8333 d. -1.67

c

. A company randomly selects 100 light bulbs every day for 40 days from its production process. If 600 defective light bulbs are found in the sampled bulbs then the estimate for the average percent defective would be a. 6.667 b. 0.167 c. 0.150 d. 0.250

b

. If a sample of 40units of output found 500 defects, then the 3-sigma upper control limit for the chart would be a. 12.50 b. 23.11 c. 37.50 d. 75.00

a

46. Control charts are typically used at the ___________ of a process. a. beginning. b. middle. c. end. d. All these answer choices are correct.

b

101. For the process to be capable of meeting design specification the process capability index must be a. less than one (1.0) b. equal to or greater than one (1.0) c. less than zero (0.0) d. equal to or greater than zero (0.0)

c

106. XYZ manufacturing has received an order to produce a rod 5 inches in diameter + .04 inch. In sample runs, the machine tool that will be making the rod has been able to produce rods with a mean diameter of 4.99 inches and a standard deviation of 0.011 inch. The process capability ratio for this process is a. -1.44 b. -1.21 c. 1.21 d. 1.44

a

42. Common (random) variation of a process depends on all the following except a. errors due to lack of training. b. the equipment and machinery used. c. the operator. d. system used for measurement.

b

43. An attribute measure is a product characteristic such a. weight. b. color. c. length. d. time

c

44. A variable measure is a product characteristic such as a. color. b. smooth. c. temperature d. tastes good

d

45. Which of the following services can be measured and monitored with control charts? a. Hospitals b. Airlines c. Banks d. All these answer choices are correct

c

47. Which of the following is not a primary purpose of statistical process control? a. to establish control limits b. to detect special cause variations c. to identify specification limits d. to determine when a process is not in control

b

48. Four common types of control charts include all of the following except: a. -chart b. t-chart c. p-chart d. c-chart

d

49. Which of the following is not a characteristic of a control chart? a. the centerline is determined using special cause (nonrandom) variations. b. the upper and lower control limits are based on special cause (nonrandom) variation. c. the centerline is determined by using the target value. d. None of these answer choices is correct.

b

50. Special cause (nonrandom) variation in a process is more likely to be detected with a. wider control limits b. narrow control limits c. wider specification limits d. narrow specification limits

a

51. Which of the following statements concerning control chart limits is true? a. the smaller the value of z, the more narrow the control limits are and the more sensitive the chart is to changes in the production process b. the larger the value of z, the more narrow the control limits are and the more sensitive the chart is to changes in the production process c. the smaller the value of z, the wider the control limits are and the less sensitive the chart is to changes in the production process d. the larger the value of z, the more narrow the control limits are and the less sensitive the chart is to changes in the production process

d

65. Consider a production process that produces batteries. A quality engineer has taken 20 samples each containing 100 batteries. The total number of defective batteries observed over the 20 samples is 200. The centerline for the control chart constructed using z equal to two is a. 0.03 b. 0.04 c. 0.05 d. 0.10

a

66. Consider a production process that produces batteries. A quality engineer has taken 20 samples each containing 100 batteries. The total number of defective batteries observed over the 20 samples is 200. The sample standard deviation is a. 0.03 b. 0.04 c. 0.05 d. 0.10

d

67. Consider a production process that produces batteries. A quality engineer has taken 20 samples each containing 100 batteries. The total number of defective batteries observed over the 20 samples is 200. The UCL for the control chart constructed using two sigma is a. 0.088 b. 0.094 c. 0.104 d. 0.160

b

68. Consider a production process that produces batteries. A quality engineer has taken 20 samples each containing 100 batteries. The total number of defective batteries observed over the 20 samples is 200. The LCL for the control chat constructed using two sigma is a. 0.01 b. 0.04 c. 0. 12 d. 0.16

b

69. Consider a production process that produces tires. A quality engineer has taken 15 samples, each containing 200 tires. The total number of defective tires over the 15 samples is 340. The centerline for the control chart is a. 0.08 b. 0.11 c. 0.16 d. 0.21

b

72. Consider a production process that produces tires. A quality engineer has taken 15 samples, each containing 200 tires. The total number of defective tires over the 15 samples is 340. The LCL for the control chat constructed using two sigma is e. 0.022 f. 0.036 g. 0.048 h. 0.066

b

73. Easy Tax is a service company that prepares tax returns. An outside auditor has examined 20 samples each containing one completed tax return. The total number of defects observed over the 20 samples is 200. What type of control chart would you recommend? a. p-chart b. c-chart c. x chart d. R chart

b

77. Easy Tax is a service company that prepares tax returns. An outside auditor has examined 20 samples each containing one completed tax return. The total number of defects observed over the 20 samples is 200. The LCL for the control chart constructed using three sigma is a. -1.6 b. 0.4 c. 3.3 d. 6.5

c

78. Marble Inc. makes countertops from a variety of high-end materials. To monitor the quality of its production processes the company randomly selects one countertop and counts the number of blemishes. The results for ten samples are shown below: Sample No. 1 2 3 4 5 6 7 8 9 10 No. of Blemishes 17 19 15 18 16 14 15 16 15 15 Given the sample information above, the average number of defects per unit for this process would be a. 160 b. 80 c. 16 d. 10

d

80. Marble Inc. makes countertops from a variety of high-end materials. To monitor the quality of its production processes the company randomly selects one countertop and counts the number of blemishes. The results for ten samples are shown below: Sample No. 1 2 3 4 5 6 7 8 9 10 No. of Blemishes 17 19 15 18 16 14 15 16 15 15 Given the sample information above, the UCL using sigma = 3 for this process would be a. 36 b. 32 c. 30 d. 28

b

86. Pizazz manufactures a 5.0 oz. energy drink of the same name. Because the cans are so small, consumers are concerned that they are not receiving the full 5 ounces in each can. A quality engineer at the company is charged with analyzing the filling process and ensuring accurate readings. On 15 different occasions over the past month, she has taken a sample of 6 energy drinks off the production line and recorded their weight. If the sum of the sample means is 80.20 ounces and the sum of the sample ranges is 12.68 ounces, what is the centerline of an R-chart for this process? a. .50 b. .85 c. 1.20 d. 1.55

c

87. Pizazz manufactures a 5.0 oz. energy drink of the same name. Because the cans are so small, consumers are concerned that they are not receiving the full 5 ounces in each can. A quality engineer at the company is charged with analyzing the filling process and ensuring accurate readings. On 15 different occasions over the past month, she has taken a sample of 6 energy drinks off the production line and recorded their weight. If the sum of the sample means is 80.20 ounces and the sum of the sample ranges is 12.68 ounces, the UCL for an R-chart of this process would be a. 0.0 b. 1.0 c. 1.7 d. 2.4

d

91. Pizazz manufactures a 5.0 oz. energy drink of the same name. Because the cans are so small, consumers are concerned that they are not receiving the full 5 ounces in each can. A quality engineer at the company is charged with analyzing the filling process and ensuring accurate readings. On 15 different occasions over the past month, she has taken a sample of 6 energy drinks off the production line and recorded their weight. If the sum of the sample means is 80.20 ounces and the sum of the sample ranges is 12.68 ounces, the LCL for an X-bar chart of this process would be a. 4.50 b. 4.65 c. 4.79 d. 4.94

c

92. Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an X-bar chart from this data, the centerline would be Samples Observations (mins) 1 2 3 4 1 5.4 4.6 6.0 1.5 2 2.8 3.9 4.6 5.4 3 5.7 3.1 2.8 2.2 4 4.1 4.3 5.3 2.8 5 2.9 1.3 4.1 3.0 6 3.3 4.3 4.2 3.9 a. 2.87 b. 3.70 c. 3.81 d. 4.28

b

93. Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an X-bar chart from this data, the 3-sigma UCL would be Samples Observations (mins) 1 2 3 4 1 5.4 4.6 6.0 1.5 2 2.8 3.9 4.6 5.4 3 5.7 3.1 2.8 2.2 4 4.1 4.3 5.3 2.8 5 2.9 1.3 4.1 3.0 6 3.3 4.3 4.2 3.9 a. 6.44 b. 5.87 c. 3.50 d. 2.82

a

96. Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an R-chart from this data, the 3-sigma UCL would be Samples Observations (mins) 1 2 3 4 1 5.4 4.6 6.0 1.5 2 2.8 3.9 4.6 5.4 3 5.7 3.1 2.8 2.2 4 4.1 4.3 5.3 2.8 5 2.9 1.3 4.1 3.0 6 3.3 4.3 4.2 3.9 a. 6.42 b. 5.87 c. 5.63 d. 5.01

c

97. Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data from one restaurant appears below. If DTG were to construct an R-chart from this data, the 3-sigma LCL would be Samples Observations (mins) 1 2 3 4 1 5.4 4.6 6.0 1.5 2 2.8 3.9 4.6 5.4 3 5.7 3.1 2.8 2.2 4 4.1 4.3 5.3 2.8 5 2.9 1.3 4.1 3.0 6 3.3 4.3 4.2 3.9 a. 2.82 b. 1.41 c. 0.00 d. -1.41

b

98. Dumplings -To-Go (DTG) provides take-out dumplings and noodle dishes to customers at its chain of drive-through restaurants. The target for a customer's waiting time is 3.0 minutes +/- 1 minute. Each month, one of the managers observes the drive-through process and collects a sample of 4 waiting times a day over a 6 day period. The data for one restaurant appears below. Calculate the process capability ratio. Is this restaurant capable of meeting DTG standards? Samples Observations (mins) 1 2 3 4 1 5.4 4.6 6.0 1.5 2 2.8 3.9 4.6 5.4 3 5.7 3.1 2.8 2.2 4 4.1 4.3 5.3 2.8 5 2.9 1.3 4.1 3.0 6 3.3 4.3 4.2 3.9 a. yes b. no c. Cannot be determined from the above information