4th Edition

ISBN: 9780073401331

Author: William Navidi Prof.

Publisher: McGraw-Hill Education

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Probability distributions are of two types, which are continuous probability distributions and discrete probability distributions. A continuous probability distribution contains an infinite number of values. For example, if time is infinite: you could co…

Normal Distribution

Suppose we had to design a bathroom weighing scale, how would we decide what should be the range of the weighing machine? Would we take the highest recorded human weight in history and use that as the upper limit for our weighing scale? This may not be a…

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Textbook Question

Chapter 4.6, Problem 1E

The lifetime (in days) of a certain electronic component that operates in a high-temperature environment is lognormally distributed with μ = 1.2 and σ = 0.4.

a. Find the mean lifetime.
b. Find the probability that a component lasts between three and six days.
c. Find the median lifetime.
d. Find the 90th percentile of the lifetimes.

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

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Chapter 4.5, Problem 26E

Chapter 4.6, Problem 2E

Chapter 4 Solutions

Statistics for Engineers and Scientists

Ch. 4.1 - After scoring a touchdown, a football team may...Ch. 4.1 - A certain brand of dinnerware set comes in three...Ch. 4.1 - When a certain glaze is applied to a ceramic...Ch. 4.1 - Let X and Y be Bernoulli random variables. Let Z =...Ch. 4.1 - A penny and a nickel are tossed. Both are fair...Ch. 4.1 - Prob. 6E Ch. 4.1 - Prob. 7E Ch. 4.2 - Let X Bin(7, 0.3). Find a. P(X = 1) b. P(X = 2)...Ch. 4.2 - Let X Bin(9, 0.4). Find a. P(X 6) b. P(X 2) c....Ch. 4.2 - Prob. 3E

Ch. 4.2 - At a certain airport, 75% of the flights arrive on...Ch. 4.2 - Of all the registered automobiles in a certain...Ch. 4.2 - A fair die is rolled 8 times. a. What is the...Ch. 4.2 - Of all the weld failures in a certain assembly,...Ch. 4.2 - A general contracting firm experiences cost...Ch. 4.2 - Several million lottery tickets are sold, and 60%...Ch. 4.2 - A quality engineer takes a random sample of 100...Ch. 4.2 - In a random sample of 100 parts ordered from...Ch. 4.2 - Of the items manufactured by a certain process,...Ch. 4.2 - Of the bolts manufactured for a certain...Ch. 4.2 - Gears produced by a grinding process are...Ch. 4.2 - A commuter must pass through three traffic lights...Ch. 4.2 - A distributor receives a large shipment of...Ch. 4.2 - A k out of n system is one in which there is a...Ch. 4.2 - Refer to Exercise 17 for the definition of a k out...Ch. 4.2 - A certain large shipment comes with a guarantee...Ch. 4.2 - An insurance company offers a discount to...Ch. 4.2 - A message consists of a string of bits (0s and...Ch. 4.2 - Let X Bin(n, p), and let Y = n X. Show that Y ...Ch. 4.2 - Porcelain figurines are sold for 10 if flawless,...Ch. 4.2 - Prob. 24E Ch. 4.2 - (Requires material from Section 3.3.) Refer to...Ch. 4.2 - If p is a success probability, the quantity p/(1 ...Ch. 4.3 - Let X Poisson(4). Find a. P(X = 1) b. P(X = 0) c....Ch. 4.3 - The number of flaws in a given area of aluminum...Ch. 4.3 - In a certain city, the number of potholes on a...Ch. 4.3 - Geologists estimate the time since the most recent...Ch. 4.3 - Prob. 5E Ch. 4.3 - One out of every 5000 individuals in a population...Ch. 4.3 - The number of hits on a certain website follows a...Ch. 4.3 - The number of cars arriving at a given...Ch. 4.3 - Prob. 9E Ch. 4.3 - Prob. 10E Ch. 4.3 - A microbiologist wants to estimate the...Ch. 4.3 - Two-dimensional Poisson process. The number of...Ch. 4.3 - The number of defective components produced by a...Ch. 4.3 - The probability that a certain radioactive mass...Ch. 4.3 - The number of flaws in a certain type of lumber...Ch. 4.3 - Grandma is trying out a new recipe for raisin...Ch. 4.3 - Mom and Grandma are each baking chocolate chip...Ch. 4.3 - Prob. 18E Ch. 4.3 - Someone claims that a certain suspension contains...Ch. 4.3 - A physicist wants to estimate the rate of...Ch. 4.3 - Prob. 21E Ch. 4.4 - Twenty air-conditioning units have been brought in...Ch. 4.4 - There are 30 restaurants in a certain town. Assume...Ch. 4.4 - The probability that a computer running a certain...Ch. 4.4 - A traffic light at a certain intersection is green...Ch. 4.4 - Refer to Exercise 4. Let Y denote the number of...Ch. 4.4 - Refer to Exercise 4. What is the probability that...Ch. 4.4 - If X Geom(p), what is the most probable value of...Ch. 4.4 - A process that fills packages is stopped whenever...Ch. 4.4 - A system is tested for faults once per hour. If...Ch. 4.4 - Prob. 10E Ch. 4.4 - In a lot of 10 microcircuits, 3 are defective....Ch. 4.4 - A lot of parts contains 500 items, 100 of which...Ch. 4.4 - Ten items are to be sampled from a lot of 60. If...Ch. 4.4 - Prob. 14E Ch. 4.4 - Prob. 15E Ch. 4.4 - A thermocouple placed in a certain medium produces...Ch. 4.4 - Prob. 17E Ch. 4.4 - Prob. 18E Ch. 4.5 - Find the area under the normal curve a. To the...Ch. 4.5 - Find the area under the normal curve a. To the...Ch. 4.5 - Let Z N(0, 1). Find a constant c for which a. P(Z...Ch. 4.5 - If X N(2, 9), compute a. P(X 2) b. P(1 X 7) c....Ch. 4.5 - The lifetime of a battery in a certain application...Ch. 4.5 - The temperature recorded by a certain thermometer...Ch. 4.5 - Scores on a standardized test are approximately...Ch. 4.5 - Weights of female cats of a certain breed are...Ch. 4.5 - The lifetime of a lightbulb in a certain...Ch. 4.5 - In a certain university, math SAT scores for the...Ch. 4.5 - Penicillin is produced by the Penicillium fungus,...Ch. 4.5 - Specifications for an aircraft bolt require that...Ch. 4.5 - A cylindrical hole is drilled in a block, and a...Ch. 4.5 - Shafts manufactured for use in optical storage...Ch. 4.5 - The fill volume of cans filled by a certain...Ch. 4.5 - The amount of paint required to paint a surface...Ch. 4.5 - A fiber-spinning process currently produces a...Ch. 4.5 - The area covered by 1 L of a certain stain is...Ch. 4.5 - Prob. 19E Ch. 4.5 - The quality-assurance program for a certain...Ch. 4.5 - Two resistors, with resistances R1 and R2, are...Ch. 4.5 - The molarity of a solute in solution is defined to...Ch. 4.5 - A binary message m, where m is equal either to 0...Ch. 4.5 - Refer to Exercise 23. Assume that if m = 0, the...Ch. 4.5 - A company receives a large shipment of bolts. The...Ch. 4.5 - Prob. 26E Ch. 4.6 - The lifetime (in days) of a certain electronic...Ch. 4.6 - The article Assessment of Dermopharmacokinetic...Ch. 4.6 - The body mass index (BMI) of a person is defined...Ch. 4.6 - The article Stochastic Estimates of Exposure and...Ch. 4.6 - If a resistor with resistance R ohms carries a...Ch. 4.6 - Refer to Exercise 5. Suppose 10 circuits are...Ch. 4.6 - The article Withdrawal Strength of Threaded Nails...Ch. 4.6 - Choose the best answer, and explain. If X is a...Ch. 4.6 - Prob. 9E Ch. 4.6 - A manufacturer claims that the tensile strength of...Ch. 4.6 - Let X1,...., Xn be independent lognormal random...Ch. 4.7 - Let T Exp(0.45). Find a. T b. T2 c. P(T 3) d....Ch. 4.7 - The time between requests to a web server is...Ch. 4.7 - A catalyst researcher states that the diameters,...Ch. 4.7 - The distance between flaws on a long cable is...Ch. 4.7 - Refer to Exercise 3. Suppose that the diameters of...Ch. 4.7 - Someone claims that the waiting time, in minutes,...Ch. 4.7 - A certain type of component can be purchased new...Ch. 4.7 - A radioactive mass emits particles according to a...Ch. 4.7 - The number of traffic accidents at a certain...Ch. 4.7 - The distance between consecutive flaws on a roll...Ch. 4.7 - A light fixture contains five lightbulbs. The...Ch. 4.8 - Prob. 1E Ch. 4.8 - Resistors are labeled 100 . In fact, the actual...Ch. 4.8 - Let T (4,0.5). a.Find T. b.Find T. c.Find P(T ...Ch. 4.8 - Prob. 4E Ch. 4.8 - Prob. 5E Ch. 4.8 - The lifetime, in years, of a type of small...Ch. 4.8 - Let T Weibull (0.5, 3). a.Find T. b.Find T....Ch. 4.8 - Prob. 8E Ch. 4.8 - Prob. 9E Ch. 4.8 - The lifetime of a certain battery is modeled with...Ch. 4.8 - The lifetime of a cooling fan, in hours, that is...Ch. 4.8 - Someone suggests that the lifetime T (in days) of...Ch. 4.8 - A system consists of two components connected in...Ch. 4.8 - Prob. 14E Ch. 4.8 - Prob. 15E Ch. 4.8 - Prob. 16E Ch. 4.8 - Prob. 17E Ch. 4.9 - Choose the best answer to fill in the blank. If an...Ch. 4.9 - Choose the best answer to fill in the blank. The...Ch. 4.9 - Let X1 and X2 be independent, each with unknown...Ch. 4.9 - Let X1,, Xn be a simple random sample from a N(,2)...Ch. 4.9 - Let X Geom (p). Find the MLE of p.Ch. 4.9 - Let X1, Xn be a random sample from a population...Ch. 4.9 - Maximum likelihood estimates possess the property...Ch. 4.9 - Let X1,, Xn be a random sample from a N(, 1)...Ch. 4.9 - Let X1, Xn be a random sample from a N(0,2)...Ch. 4.9 - Let X1,, Xn be a random sample from a N(,2)...Ch. 4.10 - Prob. 1E Ch. 4.10 - As part of a quality-control study aimed at...Ch. 4.10 - Below are the durations (in minutes) of 40...Ch. 4.10 - Prob. 4E Ch. 4.10 - Construct a normal probability plot for the PM...Ch. 4.10 - Construct a normal probability plot for the logs...Ch. 4.10 - Can the plot in Exercise 6 be used to determine...Ch. 4.10 - In the article Assessment of...Ch. 4.11 - Bottles filled by a certain machine are supposed...Ch. 4.11 - A 500-page book contains 250 sheets of paper. The...Ch. 4.11 - A commuter encounters four traffic lights each day...Ch. 4.11 - Among all the income-tax forms filed in a certain...Ch. 4.11 - Bags checked for a certain airline flight have a...Ch. 4.11 - The amount of warpage in a type of wafer used in...Ch. 4.11 - The time spent by a customer at a checkout counter...Ch. 4.11 - Drums labeled 30 L are filled with a solution from...Ch. 4.11 - The temperature of a solution will be estimated by...Ch. 4.11 - Among the adults in a large city, 30% have a...Ch. 4.11 - In a process that manufactures bearings, 90% of...Ch. 4.11 - A machine produces 1000 steel O-rings per day....Ch. 4.11 - Radioactive mass A emits particles at a mean rate...Ch. 4.11 - The concentration of particles in a suspension is...Ch. 4.11 - The concentration of particles in a suspension is...Ch. 4.11 - A battery manufacturer claims that the lifetime of...Ch. 4.11 - A new process has been designed to make ceramic...Ch. 4.11 - The manufacture of a certain part requires two...Ch. 4.11 - Seventy percent of rivets from vendor A meet a...Ch. 4.11 - Radiocarbon dating: Carbon-14 is a radioactive...Ch. 4 - An airplane has 100 seats for passengers. Assume...Ch. 4 - The number of large cracks in a length of pavement...Ch. 4 - Pea plants contain two genes for seed color, each...Ch. 4 - A simple random sample X1,,Xn is drawn from a...Ch. 4 - The Environmental Protection Agency (EPA) has...Ch. 4 - In the article Occurrence and Distribution of...Ch. 4 - Medication used to treat a certain condition is...Ch. 4 - A certain type of plywood consists of five layers....Ch. 4 - Prob. 9SE Ch. 4 - Prob. 10SE Ch. 4 - In a certain process, the probability of producing...Ch. 4 - A process that polishes a mirrored surface leaves...Ch. 4 - Prob. 13SE Ch. 4 - Prob. 14SE Ch. 4 - Thicknesses of shims are normally distributed with...Ch. 4 - The lifetime of a microprocessor is exponentially...Ch. 4 - Prob. 17SE Ch. 4 - Prob. 18SE Ch. 4 - A cereal manufacturer claims that the gross weight...Ch. 4 - Prob. 20SE Ch. 4 - Prob. 21SE Ch. 4 - Prob. 22SE Ch. 4 - Prob. 23SE Ch. 4 - Prob. 24SE Ch. 4 - Let X Geom(p). Let s 0 be an integer. a.Show...Ch. 4 - Prob. 26SE Ch. 4 - Prob. 27SE Ch. 4 - Prob. 28SE Ch. 4 - Prob. 29SE Ch. 4 - Prob. 30SE

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Solution Summary: The author calculates the probability density function of a lognormal random variable X with parameters mu =1.2andsigma =0.4.

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