Showing 21 to 30 of 687 Questions
  • A chemical system that results from a chemical reaction has two important components among others in a blend. The joint distribution describing the proportion A1 and X2 of these two components is given by(a) Give the marginal distribution of X1.(b) Give the marginal distribution of X2.(c) What is the probability that component proportions

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    465
  • A Chicago radio station believes that 40% of its listeners are younger than 25 years of age. Six hundred listeners are chosen at random. a. If the station's belief is correct, what is the probability that more than 260 of these listeners are younger than 25? b. If the station's belief is correct, the probability is 0.6 that more than how

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    3
  • A coin is flipped until 3 heads in succession occur. List only those elements of the sample space that require 6 or less tosses. Is this a discrete sample space? Explain.

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    817
  • A coin is tossed twice. Let Z denote the number of heads on the first toss and W the total number of heads on the 2 tosses. If the coin is unbalanced and a head has a 40% chance of occurring, find(a) The joint probability distribution of W and Z;(b) The marginal distribution of W;(c) The marginal distribution of Z;(d) The probability that

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    648
  • A coin is tossed until the first time a head turns up. If this occurs on the nth toss and n is odd you win 2n/n, but if n is even then you lose 2n/n. Then if your expected winnings exist they are given by the convergent series 1 − 1/2 + 1/3 − 1/4 + • • • called the alternating harmonic series. It is tempting to say that

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    171
  • A company orders components from Japan for its game player. The prices for the items that it orders are in Japanese yen. When the products are delivered, it must convert dollars into yen to pay the Japanese producer. When its next order is delivered (and must be paid for), it believes that the exchange rate of dollars to yen will take on

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    1
  • A company services copiers. A review of its records shows that the time taken for a service call can be represented by a normal random variable with a mean of 75 minutes and a standard deviation of 20 minutes. a. What proportion of service calls takes less than 1 hour? b. What proportion of service calls takes more than 90 minutes? c. Ske

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    6
  • A company services home air conditioners. It is known that times for service calls follow a normal distribution with a mean of 60 minutes and a standard deviation of 10 minutes. a. What is the probability that a single service call takes more than 65 minutes? b. What is the probability that a single service call takes between 50 and 70 mi

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    3
  • A company that has a large number of supermarket grocery stores claims that customers who pay by personal checks spend an average of $87 on groceries at these stores with a standard deviation of $22. Assume that the expenses incurred on groceries by all such customers at these stores are normally distributed. a. Find the probability that

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    0
  • A consensus forecast is the average of a large number of individual analysts’ forecasts. Suppose the individual forecasts for a particular interest rate are normally distributed with a mean of 5.0 percent and a standard deviation of 1.2 percent. A single analyst is randomly selected. Find the probability that his/ her forecast is: a. A

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    7