Exam 4: Probability

Find the indicated probability -A bin contains 71 light bulbs of which 9 are defective. If 6 light bulbs are randomly selected from the bin with replacement, find the probability that all the bulbs selected are good ones.

The table below shows the soft drinks preferences of people in three age groups. cola root beer lemon-lime under 21 years of age 40 25 20 between 21 and 40 35 20 30 over 40 years of age 20 30 35 If one of the 255 subjects is randomly selected, find the probability that the person is over 40 and drinks cola.

Determine whether the events are mutually exclusive. -Of the 52 people who answered "yes" to a question, 5 were male. Of the 77 people that answered "no" to the question, 11 were male. If one person is selected at random from the group, what is the probability that the person answered "yes" or was male?

Solve the problem. -A firm uses trend projection and seasonal factors to simulate sales for a given time period. It assigns "0" if sales fall, "1" if sales are steady, "2" if sales rise moderately, and "3" if sales rise a lot. The simulator generates the following output. 0 1 0 2 2 0 0 1 2 3 2 0 2 0 2 2 1 2 3 1 2 2 2 0 3 0 0 2 1 2 1 Estimate the probability that sales will rise moderately.

Provide an appropriate response. -Compare probabilities and odds. How can you convert odds to probabilities?

Find the indicated probability -Assume that a study of 500 randomly selected school bus routes showed that 486 arrived on time. Is it "unusual" for a school bus to arrive late?

Evaluate the expression. - $\frac { 10 ! } { 4 ! }$

Find the indicated probability -In a poll, respondents were asked whether they had ever been in a car accident. 196 respondents indicated that they had been in a car accident and 118 respondents said that they had not been in a car accident. If one of these respondents is randomly selected, what is the probability of getting someone who has been in a car accident? Round to the nearest thousandth, if necessary.

Find the indicated probability -A study conducted at a certain college shows that 60% of the school's graduates find a job in their chosen field within a year after graduation. Find the probability that 11 randomly selected graduates all find jobs in their chosen field within a year of graduating.

Determine whether the events are mutually exclusive. -100 employees of a company are asked how they get to work and whether they work full time or part time. The figure below shows the results. If one of the 100 employees is randomly selected, find the probability that the person drives alone or cycles to work. 1. Public transportation: 10 full time, 9 part time 2. Bicycle: 3 full time, 4 part time 3. Drive alone: 28 full time, 29 part time 4. Carpool: 9 full time, 8 part time

Answer the question. -What is the probability of an event that is certain to occur?

Express the indicated degree of likelihood as a probability value. -"There is a 40% chance of rain tomorrow."

Determine whether the events are mutually exclusive -Meet a man with an umbrella. Meet a man with a raincoat.

Provide an appropriate response. -Suppose a student is taking a 5-response multiple choice exam; that is, the choices are A, B, C, D, and E, with only one of the responses correct. Describe the complement method for determining the probability of getting at least one of the questions correct on the 15-question exam. Why would the complement method be the method of choice for this problem?

Determine whether the events are mutually exclusive -Suppose you are playing a game of chance. If you bet $7 on a certain event, you will collect $280 (including your $7 bet)if you win. Find the odds used for determining the payoff.

Find the indicated probability -When a pair of dice are rolled there are 36 different possible outcomes: 1-1, 1-2, ... 6-6. If a pair of dice are rolled 4 times, what is the probability of getting a sum of 7 every time?

Use a graphing calculator to develop a simulation of the given problem (100 trials). Describe the simulation, then estimate the probability based on its results. -Assume that ten percent of us are left-handed. The probability of getting at least two left-handed people in a group of 7.

Provide an appropriate response. -Define mutually exclusive events and independent events. Give an example of each.

Provide an appropriate response. -Discuss why the relative frequency method of computing probabilities might be chosen over the classical method.

Use a graphing calculator to develop a simulation of the given problem (100 trials). Describe the simulation, then estimate the probability based on its results. -The probability of getting a total of 15 when four dice are thrown.