A coin is tossed four times.The probability is ? or 0.25 that all four tosses will result in a head face up.
Answer Correct Answer: False A firm offers routine physical examinations as part of a health service program for its employees. The exams showed that 8% of the employees needed corrective shoes, 15% needed major dental work and 3% needed both corrective shoes and major dental work. What is the probability that an employee selected at random will need either corrective shoes or major dental work? Correct Answer: 0. 20
A group of employees of Unique Services will be surveyed about a new pension plan. In-depth interviews with each employee selected in the sample will be conducted. The employees are classified as follows. What is the probability that the first person selected is classified as a maintenance employee? Correct Answer: 0. 025 A probability is a number from -1 to +1. Correct Answer: False When are two events mutually exclusive? Correct Answer: If one event occurs, then the other cannot There are 10 rolls of film in a box and 3 are defective.
Two rolls are selected without replacement. What is the probability of selecting a defective roll followed by another defective roll? Correct Answer: 1/15 or about 0. 07 Three defective electric toothbrushes were accidentally shipped to a drugstore by the manufacturer along with 17 non-defective ones. What is the probability that the first two electric toothbrushes sold will be returned to the drugstore because they are defective? Correct Answer: 3/190 or 0. 01579 The first card selected from a standard 52-card deck was a king.
If it is NOT returned to the deck, what is the probability that a king will be drawn on the second selection? Correct Answer: 3/51 or 0. 0588 The first card selected from a standard 52-card deck was a king. If it is returned to the deck, what is the probability that a king will be drawn on the second selection? Correct Answer: 1/13 or 0. 077 If there are ‘m’ ways of doing one thing and ‘n’ ways of doing another thing, the multiplication formula states that there are (m) • (n) ways of doing both. Correct Answer: True
A study by the National Park Service revealed that 50% of the vacationers going to the Rocky Mountain region visit Yellowstone Park, 40% visit the Grand Tetons and 35% visit both. What is the probability that a vacationer will visit at least one of these magnificent attractions? Correct Answer: 0 The closer a probability is to 0, the more likely the event will happen. Correct Answer: False The classical approach to probability requires that the outcomes of an experiment are not equally likely. Correct Answer: False The numbers 0 through 9 are used in code groups of four to identify an item of clothing.
Code 1083 might identify a blue blouse, size medium. The code group 2031 might identify a pair of pants, size 18, and so on. Repetitions of numbers are not permitted, i. e. , the same number cannot be used more than once in a total sequence. As examples, 2256, 2562 or 5559 would not be permitted. How many different code groups can be designed? Correct Answer: 5,040 A discrete random variable can have only certain clearly separated values. Correct Answer: True A listing of all possible outcomes of an experiment and their corresponding probability of occurrence is called a _____________.
Correct Answer: Probability distribution A statistics professor receives an average of five e-mail messages per day from students. Assume the number of messages approximates a Poisson distribution. What is the probability that on a randomly selected day she will have five messages? Correct Answer: 0. 175 David’s gasoline station offers 4 cents off per gallon if the customer pays in cash and does not use a credit card. Past evidence indicates that 40% of all customers pay in cash. During a one-hour period twenty-five customers buy gasoline at this station.
What is the probability that more than ten and less than fifteen customers pay in cash? Correct Answer: 0. 380 David’s gasoline station offers 4 cents off per gallon if the customer pays in cash and does not use a credit card. Past evidence indicates that 40% of all customers pay in cash. During a one-hour period twenty-five customers buy gasoline at this station. What is the probability that at least ten pay in cash? Correct Answer: 0. 575 Which of the following is NOT a characteristic of a binomial probability distribution? Correct Answer:
Each outcome results from two trials The weight of an offensive linesman may be 205. 15 pounds, 210. 23 pounds, 225. 05 pounds or 219. 14 pounds. What is this an illustration of? Correct Answer: Continuous random variable The variance of a binomial distribution is found by ? ? (1 – ? ). Correct Answer: True The mean of a binomial distribution is the product of n and ?. Correct Answer: True A true-false test consists of six questions. If you guess the answer to each question, what is the probability of getting all six questions correct? Correct Answer: 0. 016