Question: Discuss how the precision of a measurement

> A snail crawls at a pace of 5.0 cm/min. Express the snail's speed in (a) ft./s and (b) mi/h.

> (a) How many square centimeters are in 1 square foot? (1 in = 2.54 cm.) (b) How many square centimeters are in 1 square meter?

> Express this product in units of km3 with the appropriate number of significant figures:

> A molecule in air is moving at a speed of 459 m/s. How far would the molecule move during 7.00 ms (milliseconds) if it didn't collide with any other molecules?

> Blood flows through the aorta at an average speed of v = 18 cm/s. The aorta is roughly cylindrical with a radius r = 12 mm. The volume rate of blood flow through the aorta is π r2v. Calculate the volume rate of blood flow through the aorta in L/min.

> The intensity of the Sun's radiation that reaches Earth's atmosphere is 1.4 kW/m2 (kW = kilowatt; W = watt). Convert this to W/cm2.

> At the end of 2006 an expert economist predicted a drop in the value of the U.S. dollar against the euro of 10% over the next five years. If the exchange rate was $1.27 to 1 euro on November 5, 2006, and was $1.45 to 1 euro on November 5, 2007, what was

> The first modern Olympics in 1896 had a marathon distance of 40 km. In 1908, for the Olympic marathon in London, the length was changed to 42.195 km to provide the British royal family with a better view of the race. This distance was adopted as the offi

> A nerve impulse travels along a myelinated neuron at 80 m/s. What is this speed in (a) mi/h and (b) cm/ms?

> A beaker contains 255 mL of water. What is the volume of the water in (a) cubic centimeters? (b) cubic meters?

> The quantity of energy Q transferred by heat conduction through an insulating pad in time interval Δt is described by Q/Δt = κA ΔT/d, where κ is the thermal conductivity of the material, A is the face area of the pad (perpendicular to the direction of he

> The length of the river span of the Brooklyn Bridge is 1595.5 ft. The total length of the bridge is 6016 ft. Convert both of these lengths to meters.

> The label on a small soda bottle lists the volume of the drink as 355 mL. Use the conversion factor 1 gal = 128 fl oz. (a) How many fluid ounces are in the bottle? (b) A competitor's drink is labeled 16.0 fl oz. How many milliliters are in that drink?

> A cell membrane is 7.0 nm thick. How thick is it in inches?

> The density of body fat is 0.9 g/cm3. Find the density in kg/m3.

> Solve the following problem and express the answer in meters per second (m/s) with the appropriate number of significant figures: (3.21 m)/ (7.00 ms) =? Hint: Note that ms stands for milliseconds.

> Solve the following problem and express the answer in meters with the appropriate number of significant figures and in scientific notation:

> Given these measurements, identify the number of significant figures and rewrite in standard scientific notation. (a) 0.005 74 kg (b) 2 m (c) 0.450 × 10−2 m (d) 45.0 kg (e) 10.09 × 104 s (f) 0.095 00 × 105 mL

> Rank these measurements in order of the number of significant figures, from least to greatest. (a) 7.68 g (b) 0.420 kg (c) 0.073 m (d) 7.68 × 105 g (e) 4.20 × 103 kg (f) 7.3 × 10−2 m (g) 2.300 × 104 s

> Find the product below and express the answer with units and in scientific notation with the appropriate number of significant figures:

> On Monday, a stock market index goes up 5.00%. On Tuesday, the index goes down 5.00%. What is the net percentage change in the index for the two days? Explain why it is not zero.

> A study finds that the metabolic rate of mammals is proportional to m3/4, where m is total body mass. By what factor does the metabolic rate of a 70 kg human exceed that of a 5.0 kg cat?

> Samantha is 1.50 m tall on her eleventh birthday and 1.65 m tall on her twelfth birthday. By what factor has her height increased? By what percentage?

> A homeowner is told that she must increase the height of her fences 37% if she wants to keep the deer from jumping in to eat the foliage and blossoms. If the current fence is 1.8 m high, how high must the new fence be?

> 55 mi/h is approximately (a) 90 km/h (b) 30 km/h (c) 10 km/h (d) 2 km/h

> By what factor does the volume of a cube increase if the length of the edges is doubled? (a) 16 (b) 8 (c) 4 (d) 2

> One kilometer is approximately (a) 2 miles (b) 1/2 mile (c) 1/10 mile (d) 1/4 mile

> How many significant figures should be written in the product 0.007840 6 m × 9.450 20 m? (a) 3 (b) 4 (c) 5 (d) 6 (e) 7

> Rank the results of the following calculations in order of the number of significant figures, from least to greatest. (a) 6.85 × 10−5 m + 2.7 × 10−7 m (b) 702.35 km + 1897.648 km (c) 5.0 m × 4.302 m (d) (0.040/π) m

> The “scale” of a certain map is 1/10 000. This means the length of, say, a road as represented on the map is 1/10 000 the actual length of the road. What is the ratio of the area of a park as represented on the map to the actual area of the park?

> Refer to Exercise 8-21 and the data shown in Table 8-23. Construct a standardized p-chart and discuss your conclusions. Data from Exercise 8-21: Observations are taken from the output of a company making semiconductors. Table 8-23 shows the sample size

> A computer monitor manufacturer subcontracts its major parts to four vendors: A, B, C, and D. Past records show that vendors A and C provide 30% of the requirements each, vendor B provides 25%, and vendor D provides 15%. In a random sample of 10 parts, 4

> Distinguish between producer’s risk and consumer’s risk. In this context, explain the terms acceptable quality level and limiting quality level. Discuss instances for which one type of risk might be more important than the other.

> Explain the difference between the decision-making procedure using Forms 1 and 2 for variable sampling plans that are designed to estimate the proportion of nonconforming items.

> What are the parameters of a variable sampling plan for which the process average quality is of interest? Explain the working procedure of such a plan when single and double specification limits are given.

> What are the advantages and disadvantages of variable sampling plans over those for attributes?

> Discuss the assumptions made in Deming’s kp rule. When would you use this rule?

> Compare and contrast chain sampling and sequential sampling plans. When are they used?

> Discuss the advantages and disadvantages of sampling.

> Suppose that the dimension of an assembly has to be within certain tolerances. Discuss how tolerances could be set for the components given that the difference between two component dimensions comprises this assembly dimension. Assume that the inherent v

> Suppose that the time to complete a project is the sum of several independent operations. If the means and standard deviations of the independent operations are known, determine the mean and standard deviation of the project completion time. If the opera

> What condition must exist prior to calculating the process capability? Discuss how process capability can be estimated through control charts.

> Discuss the indices for measuring quality costs. Give examples where each might be used.

> Compare the capability indices Cpk, Cpm, and Cpmk and discuss what they measure in the process. When would you use Cpq?

> What are the advantages of having a process spread that is less than the specification spread? What should the value of Cp be in this situation? Could Cpk be here?

> Is it possible for a process to be in control and still produce nonconforming output? Explain. What are some corrective measures under these circumstances?

> What are statistical tolerance limits? Explain how they differ from natural tolerance limits.

> Explain the difference between natural tolerance limits and specification limits. How does a process capability index incorporate both of them? What assumptions are made in constructing the natural tolerance limits?

> Distinguish between gage repeatability and gage reproducibility in the context of measuring unloading times of super tankers.

> Discuss the importance of identifying an appropriate distribution of the quality characteristic in process capability analysis. Address this in the context of waiting time for service in a fast-food restaurant during lunch hour.

> Explain the difference between specification limits and control limits. Is there a desired relationship between the two?

> Discuss the role of the customer in influencing the proportion-nonconforming chart. How would the customer be integrated into a total quality systems approach?

> Classify each of the following into the cost categories of prevention, appraisal, internal failure, and external failure: (a) Vendor selection (b) Administrative salaries (c) Downgraded product (d) Setup for inspection (e) Supplier control (f) External c

> Is it possible for a process to be in control and still not meet some desirable standards for the proportion nonconforming? How would one detect such a condition, and what remedial actions would one take?

> Discuss the assumptions that must be satisfied to justify using a p-chart. How are they different from the assumptions required for a c-chart?

> What are the advantages and disadvantages of the standardized p-chart as compared to the regular proportion-nonconforming chart?

> How does changing the sample size affect the center line and the control limits of a p-chart?

> The CEO of a company has been charged with reducing the proportion nonconforming of the product output. Discuss which control charts should be used and where they should be placed.

> Discuss the significance of an appropriate sample size for a proportion-nonconforming chart.

> What are the advantages and disadvantages of control charts for attributes over those for variables?

> Explain the setting under which a U-chart would be used. How does the U-chart incorporate the user’s perception of the relative degree of severity of the different categories of defects?

> Meeting customer due dates is an important goal. What attribute or variables control charts would you select to monitor? Discuss the underlying assumptions in each case.

> Distinguish between 3σ limits and probability limits. When would you consider constructing probability limits?

> A quality improvement program has been instituted in an organization to reduce total quality costs. Discuss the impact of such a program on prevention, appraisal, and failure costs.

> Explain why a p- or c-chart is not appropriate for highly conforming processes.

> Explain the conditions under which a u-chart would be used instead of a c-chart.

> Discuss the impact of the control limits on the average run length and the operating characteristic curve.

> Distinguish between a nonconformity and a nonconforming item. Give examples of each in the following contexts: (a) Financial institution (b) Hospital (c) Microelectronics manufacturing (d) Law firm (e) Non-profit organization

> A new hire has been made in a management consulting firm and data are monitored on response time to customer queries. Discuss what the patterns on an and R-chart might look like as learning on the job takes place.

> Explain the difference in interpretation between an observation falling below the lower control limit on an and one falling below the lower control limit on an R-chart. Discuss the impact of each on the revision of control charts in the con

> Patient progress in a health care facility is monitored over time for a certain diagnosis related group according to a few vital characteristics (systolic blood pressure, diastolic blood pressure, total cholesterol, weight). The characteristics, however,

> A start-up company promoting the development of new products can afford only a few observations from each product. Thus, a critical quality characteristic is selected for monitoring from each product. What type of control chart would be suitable in this

> What are some considerations in the interpretation of control charts based on standard values? Is it possible for a process to be in control when its control chart is based on observations from the process but to be out of control when the control chart

> Discuss specific characteristics that could be monitored through variable control charts, the form of data to collect, and the appropriate control chart in the following situations: (a) Waiting time to check in baggage at an airport counter (b) Product a

> An intermodal logistics company uses trucks, trains, and ships to distribute goods to various locations. What might be the various quality costs in each of the categories of prevention, appraisal, internal failure, and external failure?

> Discuss the preliminary decisions that must be made before you construct a control chart. What concepts should be followed when selecting rational samples?

> Describe the use of the Pareto concept in the selection of characteristics for control charts.

> Lung congestion may occur in illness among infants. However, it is not easily verifiable without radiography. To monitor an ill infant to predict whether lung opacity will occur on a radiograph, data are kept on age, respiration rate, heart rate, tempera

> What is the motivation behind constructing multivariate control charts? What advantages do they have over control charts for individual characteristics?

> Discuss the appropriate setting for using a modified control chart and an acceptance control chart. Compare and contrast the two charts.

> Discuss the importance of risk adjustment in monitoring mortality and related measures in a health care setting.

> What are the conditions under which a moving-average control chart is preferable? Compare the moving-average chart with the geometric moving-average chart.

> What are the advantages and disadvantages of cumulative sum charts compared to Shewhart control charts?

> Explain the concept of process capability and when it should be estimated. What is its impact on non-conformance? Discuss in the context of project completion time of the construction of an office building.

> An optical sensor has a Weibull time-to-failure distribution with a scale parameter of 300 hours and a shape parameter of 0.5. What is the reliability of the sensor after 500 hours of operation? Find the mean time to failure.

> Control charts are maintained on individual values on patient recovery time for a certain diagnosis-related group. What precautions should be taken in using such charts and what are the assumptions?

> An OEM in the automobile industry is considering an improvement in its order processing system with its tier 1 suppliers. Discuss appropriate measures of quality. What are some special and some common causes in this environment?

> An electronic component in a video recorder has an exponential time-to-failure distribution. What is the minimum mean time to failure of the component if it is to have a probability of 0.92 of successful operation after 6000 hours of operation?

> A transistor has an exponential time-to-failure distribution with a constant failure rate of 0.00006/hour. Find the reliability of the transistor after 4000 hours of operation. What is the mean time to failure? If the repair rate is 0.004/hour, find the

> Refer to Exercise 9-33 on the order completion time of a logistics firm. Upon conducting a methods study of the various operations, the firm was able to reduce the mean times of operation 1 to 5.8 hours and that of operation 3 to 7.5 hours. Assume that t

> Refer to Exercise 9-39. Find the sample size needed to construct a one-sided lower nonparametric statistical tolerance limit. It should contain 90% of the population with a probability of 0.95. How will the limit be found? Data from Exercise 9-39: Find

> Find the sample size required for two-sided nonparametric statistical tolerance limits for the viscosity of a grease used as a lubricant. It should contain 99% of the population with a probability of 0.95. How will the interval be found?

> The body mass index (BMI) is a measure of obesity and equals a person’s weight (in kilograms) divided by the height (in meters) squared. For a certain diagnosis related group of 20 patients, the following natural tolerances were obtained on weight (60± 5

> In solar cells, the exposed surface area is the characteristic of interest. The tolerances on the length and width of the cells are 4 ±0.06 cm and 5± 0.09 cm, respectively. Assuming these dimensions to be independent of each other and each normally distr

> A cylindrical piece is used in an assembly in which the weight is to be controlled. The tolerances on diameter and height, on the basis of five observations, are 2 ±0.06 cm and 6 ±0.06 cm, respectively. Assume that the dimensions are independent of each

> Consider the data on call waiting time of customers in a call center. The call center has set a goal of waiting time not to exceed 35 seconds. (a) Test to see (using α =0.05) if conducting capability analysis using normal distribution is appropriate. (b)

> Measurements on the pH values of a chemical compound are taken at random by two operators. Fifteen samples are randomly chosen, with each operator measuring each sample twice. The data are shown in Table 9-10. Specifications on pH are 6.5 ±

> A financial institution wants to improve proposal preparation time for its clients. Discuss the actions to be taken in reducing the average preparation time and the variability of preparation times.

> A logistics firm has identified four operations, which are to be conducted in succession, for an order to be processed. The tolerances (in hours) are shown in Table 9-9. Assume that the tolerances are independent of each other and that the time in each p

> In a piston assembly, the specifications for the piston diameter are 12 ±0.5 cm, and those for the cylinder diameter are 12.10 ±0.4 cm. Assume that the natural tolerance limits coincide with the specifications. A clearance fit is required for the assembl