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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The stamping machine on a production line periodically is taken off-line for maintenance. Assume that the amount of time the machine is off-line is uniformly distributed between 15 and 30 minutes.   186) What is the probability that the machine is off-line for more.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Each member of a random sample of 20 business economists was asked to predict the rate of inflation for the coming year. Assume that the predictions for the whole population of business economists follow a normal distribution with standard deviation 2%.   134) The.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The number of hours spent studying by students on Michigan State campus in the week before final exams follows a normal distribution with standard deviation 9.5 hours. A random sample of these students is taken to estimate the population mean number of.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The amount of time you have to wait at a dentist's office before you are called in is uniformly distributed between zero and twenty minutes.   168) What is the probability that you have to wait more than 8 minutes?   169) What is the probability.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The average amount of time between a score by either team in college soccer games is 15.2 minutes. Suppose that the time between scores follows an exponential distribution.   171) What is the probability that a soccer game goes for 45 minutes without either.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The distribution of IQ scores for high school graduates is normally distributed with mean μ = 104 and standard deviation σ = 16.   233) Find the probability a person chosen at random from this group has an IQ score above 146.00.   234) What fraction.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The filling machine at a bottling plant is operating correctly when the variance of the fill amount is equal to 0.3 ounces. Assume that the fill amounts follow a normal distribution.   77) What is the probability that for a sample of 30 bottles,.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider a random sample of size n =1800 from a binomial probability distribution with P = 0.40, and X = number of successes.   218) Find the mean and standard deviation of the proportion of successes. 219) Find the probability that the percentage of successes.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A random sample of size n = 25 is obtained from a normally distributed population with population mean μ = 200 and variance σ2 = 100.   125) What are the mean and standard deviation of the sampling distribution for the sample means? 126) What.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: It has been found that 62.1% of all unsolicited third class mail delivered to households goes unread. Over the course of a month, a household receives 100 pieces of unsolicited mail.   73) What is the mean of the sample proportion of pieces of.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: According to the Internal Revenue Service, 80% of all tax returns lead to a refund. A random sample of 100 tax returns is taken.   118) What is the mean of the sampling distribution of the sample proportion of returns leading to refunds?   119) What.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A random variable X is normally distributed with mean of 50 and variance of 50, and a random variable Y is normally distributed with mean of 100 and variance of 200.   207) Given the random variables X and Y have a correlation coefficient.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Suppose x is normally distributed with a mean of 75 and a standard deviation of 4.   236) Find the 90th percentile. 237) Find the 95th percentile.   238) Find the 5th percentile.   239) A normal random variable x has an unknown mean μ and standard deviation σ.
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    41) What is the probability that in a particular month the office receives more than 310 orders? A) 0.7823 B) 0.2826 C) 0.7174 D) 0.2177   42) The probability is 0.3 that the sales office receives less than how many orders? A) 310.9 B) 285.1 C) 290.0 D) 306.0   43) What is the area under the normal curve between Z =.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A professor sees students during regular office hours. Times spent with students follow an exponential distribution with mean of 12 minutes.   203) Find the probability that a given student spends less than 15 minutes with the professor.   204) Find the probability that a given.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A store has determined that 28% of all refrigerators purchasers will also purchase a service agreement. In one month, 250 refrigerators are sold to customers who can be regarded as a random sample of all purchasers.   122) What are the mean and standard.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider a random sample of size n =1800 from a binomial probability distribution with P = 0.40, and X = number of successes.   212) Find the mean and standard deviation of the number of successes.   213) Find the probability that the number of successes.
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    121) Although the binomial distribution is discrete and the normal distribution is continuous, the normal distribution is a good approximation for the binomial whenever nP(1 - P) > 9 where n = number of trials, and P = the probability of success in any given trial.   122) The total area under.
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    151) If a data set is approximately normally distributed, then its normal probability plot will be S-shaped.   152) The mean and variance of any normal distribution are always zero and one, respectively.   153) The proportion of the total area under the normal curve that lies within ± one standard deviation of the.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Let the random variable Z follow a standard normal distribution.   176) What is P(Z > 0.29)?   177) What is P(Z < 1.23)?   178) What is P(Z > -0.52)?   179) What is P(-0.44 < Z < 1.2)? 180) As manager of a pizza shop, you are responsible for.
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  1) The shape of the uniform probability distribution is: A) negatively skewed. B) positively skewed. C) bell-shaped. D) rectangular.   2) Sales, investment, consumption, costs, and revenues are economic and business measures which can be represented by: A) discrete variable. B) fixed variables. C) continuous random variables. D) coefficients.   3) Because measurements of random variables are rounded to some value, mathematical.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Times spent studying by students in the week before final exams follow a normal distribution with standard deviation 9 hours. A random sample of 5 students was taken in order to estimate the mean study time for the population of all students.   107).
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Candidates for employment at a city fire department are required to take a written aptitude test. Scores on this test are normally distributed with mean 260 and standard deviation 51. A random sample of nine test scores was taken.   104) What are the.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The average checking account balance at a local bank is $1,742 with a standard deviation of $132. A random sample of 70 accounts is selected.   85) What is the probability that the average balance for these accounts is less than $1,700? 86) The probability.
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    11) The shape of the normal probability density function is a symmetric bell-shaped curve centered on the: A) variance. B) standard deviation. C) coefficient. D) mean. 12) We can convert any normal distribution to a distribution with a mean 0 and a variance 1. What is the distribution called? A) Poisson distribution B) standard normal distribution C) hypergeometric.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Given a population with mean μ=120 and variance σ2 = 81, the central limit applies when the sample size is large-enough. A random sample of size n = 36 is obtained.   95) What are the mean and standard deviation of the sampling distribution.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Suppose that the time between successive occurrences of an event follows an exponential distribution with mean 1/λ minutes. Assume that an event occurs.   225) Show that the probability that more than 4 minutes elapses before the occurrence of the next event is e-4λ.   226).
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The life of a new type of light bulb is uniformly distributed between 1,200 and 1,600 hours.   192) The probability is 70% that a randomly-selected light bulb will last at least how long.   193) What is the probability that a randomly-selected light bulb burns.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: It is estimated that 1.3% of all items produced on an assembly line have some form of defect. You randomly select 60 items for inspection.   82) What is the probability that more than 1.5% of the 60 items have some form of defect?   83).
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    161) Normal probability plots provide a way to test the assumption that the normal distribution is a close approximation to the actual unknown distribution that supplied the data we are analyzing.   162) We can reduce the number of different statistical procedures needed to solve business problems by applying procedures based on.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Monthly rates of return on the shares of a particular common stock are independent of one another and normally distributed with a standard deviation of 1.8. A sample of 15 months is taken.   129) Find the probability that the sample standard deviation is.
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    111) Which type of random variables are used to model market values of various stock prices, production and sales patterns, and studies of import and export behavior? A) consistent B) marginal C) hypergeometric D) jointly distributed   112) The combinations of continuous random variables whose development is based on operation with expected values and does not.
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THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A continuous random variable X has the probability density function: f(x) = 2e-2x, x ≥ 0.   228) What is the distribution of the random variable X?   229) Find the mean and standard deviation of X.   230) What is the probability that x is between 1.
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