## Description

**MATH 302 Quiz 2 – Question and Answers**

**Question 1 of 20 **

- The probability of an event and the probability of its complement always sum to:
- A jar contains four white marbles, five red marbles, and six black marbles. If a marble is selected at random, find the probability that it is white or black .
- If two events are independent, what is the probability that they both occur?
- If two events are mutually exclusive, what is the probability that one or the other occurs?
- What type of probability uses sample spaces to determine the numerical probability that an event will occur?

**Part 2 of 6**

- Find the variance of the following probability distribution.
- If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices.
- The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.
- A researcher surveyed college students to study their opinion about the proposed change in smoking rules. The researcher asked a group of 30 students: 12 of them supported the change, 13 of them did not, and 5 had no opinion. This is not a binomial model because…
- The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.

**Part 3 of 6**

- In February 2002 the Argentine peso lost 70% of its value compared to the United States dollar. This devaluation drastically raised the price of imported products. According to a survey conducted by AC Nielsen in April 2002, 68% of the consumers in Argentina were buying fewer products than before the devaluation, 24% were buying the same number of products, and 8% were buying more products. Furthermore, in a trend toward purchasing less-expensive brands, 88% indicated that they had changed the brands they purchased. Suppose the following complete set of results were reported. Use the following data to answer this question. Given that a consumer changed brands, what then is the probability that the consumer purchased fewer products than before? Place your answer, rounded to 4 decimal places, in the blank.
- A DVD rental business determines that customers will rent X number of DVDs according to the following distribution:
- The annual returns, in percentages, on stocks A and B for three possible states of the economy are given in the table below.
- Click to see additional instructions. In February 2002 the Argentine peso lost 70% of its value compared to the United States dollar. This devaluation drastically raised the price of imported products. According to a survey conducted by AC Nielsen in April 2002, 68% of the consumers in Argentina were buying fewer products than before the devaluation, 24% were buying the same number of products, and 8% were buying more products. Furthermore, in a trend toward purchasing less-expensive brands, 88% indicated that they had changed the brands they purchased. Suppose the following complete set of results were reported. Use the following data to answer this question.

**Part 4 of 6**

- If a coin is tossed seven times, how many different outcomes are possible? Place your answer in the blank. Do not use any decimal places or commas. For example, 345 would be a legitimate entry. 128
- A particular brand of women’s jeans is available in seven different sizes, three different colors, and three different styles. How many different jeans does the store manager need to order to have one pair of each type of jean? Place your answer in the blank. Do not use any decimal places or commas. For example, 45 would be a legitimate entry. 63
- An ice cream vendor sells three flavors: chocolate, strawberry, and vanilla. Forty five percent of the sales are chocolate, while 30% are strawberry, with the rest vanilla flavored. Sales are by the cone or the cup. The percentages of cones sales for chocolate, strawberry, and vanilla, are 75%, 60%, and 40%, respectively. For a randomly selected sale, define the following events:
- A certain system has two components. There are 10 different models of the first component and 10 different of the second. Any first component can be paired with any second component. A salesman must select 2 of the first component and 3 of the second to take on a sales call. How many different systems can the salesman select? Place your answer in the blank. Do NOT use commas. For example, 2350 would be a legitimate response. 5400
- Jim and Mike go to a coffee shop during their lunch break and toss a coin to see who will pay. The probability that Mike will pay three days in a row is 0.125.
- True or False: The probability of a success must remain the same for each trial in a binomial experiment.