front 1 Determine whether the following is a probability distribution. If not, identify the requirement that is not satisfied: A police department reports that the probabilities that 0, 1, 2, 3, and 4 car thefts will be reported in a given day are 0.183, 0.311, 0.264, 0.150, and 0.064, respectively. | back 1 Not a probability distribution. The sum of the P(x)'s is not 1, since 0.9720 ≠ 1.000. |
front 2 A company manufactures batteries in batches of 25 and there is a 3% rate of defects. Find the standard deviation for the number of defects per batch. | back 2 0.9 |
front 3 A machine has 12 identical components which function independently. The probability that a component will fail is 0.2. The machine will stop working if more than three components fail. Find the probability that the machine will be working. | back 3 0.795 |
front 4 Suppose you pay $3.00 to roll a fair die with the understanding that you will get back $5.00 for rolling a 1 or a 6, nothing otherwise. What is your expected value? | back 4 -$1.33 |
front 5 A company manufactures batteries in batches of 18 and there is a 3% rate of defects. Find the mean number of defects per batch. | back 5 0.5 |
front 6 The brand name of a certain chain of coffee shops has a 54% recognition rate in the town of Coffleton. An executive from the company wants to verify the recognition rate as the company is interested in opening a coffee shop in the town. He selects a random sample of 10 Coffleton residents. Find the probability that exactly 4 of the 10 Coffleton residents recognize the brand name. | back 6 0.169 |
front 7 The Acme Candy Company claims that 8% of the jawbreakers it produces actually result in a broken jaw. Suppose 9571 persons are selected at random from those who have eaten a jawbreaker produced at Acme Candy Company. Would it be unusual for this sample of 9571 to contain 797 persons with broken jaws? | back 7 No, 797 people are within 2 standard deviations of the mean. |
front 8 Determine whether the following is a random variable, and if it is, whether it is discrete or continuous: The number of pixels in a digital photo. | back 8 Discrete |
front 9 Find the mean of the given probability distribution: The probabilities that a batch of 4 computers will contain 0, 1, 2, 3, and 4 defective computers are 0.5470, 0.3562, 0.0870, 0.0094, and 0.0004, respectively. Round answer to the nearest hundredth. | back 9 µ = 0.56 |
front 10 The probabilities that a batch of 4 computers will contain 0, 1, 2, 3, and 4 defective computers are 0.4521, 0.3970, 0.1307, 0.0191, and 0.0010, respectively. Find the standard deviation for the probability distribution. | back 10 σ = 0.77 |