Exam 4: Probability

Refer to the table which summarizes the results of testing for a certain disease Positive Test Result Negative Test Result Subject has the disease Subject does not have the disease 111 4 11 172 If one of the results is randomly selected, what is the probability that it is a false negative (test indicates the person does not have the disease when in fact they do)? What does this probability suggest about the accuracy of the test?

Use technology to develop a simulation of the given problem (100 trials). simulation, then estimate the probability based on its results. The probability of getting at least two boys in a family of seven children.

In a recent year, 304 of the approximately 300,000,000 people in the United States were struck by lightning. The probability that a randomly selected person in the United States will be struck by lightning this year is 0.00000101. Is a golfer reasoning correctly if he or she is caught out in a thunderstorm and does not seek shelter from lightening because the probability of being struck is so small?

Describe the process for making a tree diagram and give an example

A statistics student plans to use a TI-84 Plus calculator on her final exam. From past experience, she estimates there is a 0.92 probability that the calculator will work on any given day. Because the final exam is so important, she plans to bring in two calculators in case one loses power. Does she gain much by bringing in the backup calculator? Use the probability that she will be able to complete her exam with a working calculator.

Refer to the table which summarizes the results of testing for a certain disease Positive Test Result Negative Test Result Subject has the disease 87 9 Subject does not have the disease 27 312 A test subject is randomly selected and tested for the disease. What is the probability the subject has the disease given that the test result is negative.

A study conducted at a certain college shows that 65% 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. Round to the Nearest thousandth if necessary.

In a recent year, 304 of the approximately 300,000,000 people in the United States were struck by lightning. Estimate the probability that a randomly selected person in the United States will be struck by lightning this year.

Evaluate the expression ${ } _ { 8 } P _ { 4 }$

Assume that a study of 500 randomly selected airplane routes showed that 482 arrived on time. Select the correct interpretation of the probability of an airplane arriving late. Interpret an event as significant if its probability is less than or equal to 0.05.

Some employers use lie detector tests to screen job applicants. Lie detector tests are not completely reliable. Suppose that in a lie detector test, 65% of lies are identified as lies and that 14% of true statements are also identified as lies. A company gives its job applicants a Polygraph test, asking "Did you tell the truth on your job application?". Suppose that 93% of The job applicants tell the truth during the polygraph test. What is the probability that a person Who fails the test was actually telling the truth?

Some employers use lie detector tests to screen job applicants. Lie detector tests are not completely reliable. Suppose that in a lie detector test, 65% of lies are identified as lies and that 14% of true statements are also identified as lies. A company gives its job applicants a Polygraph test, asking "Did you tell the truth on your job application?" Suppose that 93% of The job applicants tell the truth during the polygraph test. What is the probability that a person Who fails the test was actually telling the truth?

What important question must you answer before computing an "or" probability? How does the answer influence your computation?

An author has six different books in print. If those six books are stacked in a random order, what is the probability that they are arranged in alphabetical order from top to bottom? How about seven different books?

The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency table below summarizes the results. Waiting Time (minutes) Number of Customers 0-3 9 4-7 10 8-11 12 12-15 4 16-19 4 20-23 2 24-27 2 If we randomly select one of the customers represented in the table, what is the probability that the waiting time is at least 12 minutes or between 8 and 15 minutes?

In a certain town, 10% of people commute to work by bicycle. If a person is selected randomly from the town, what are the odds against selecting someone who commutes by bicycle?

Of the thirteen different women Calvin asks for a date, at least one of them accepts. Provide a written description of the complement of the given event.

If you drew one card from a standard deck, would it be "significant" to draw a 5? Answer the question, considering an event to be "significant" if its probability is less than or equal to 0.05.

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 drinks root beer given that they are over 40 .

In the Texas Pick 3 Lottery, you can bet $\$ 1$ by selecting the exact order of three digits between 0 and 9 inclusive, so the probability of winning is $1 / 1000$ . If the same three numbers are draw in the same order, you collect $\$ 500$ , so your net profit is $\$ 499$ . Find the actual odds against winning and the payoff odds. The website indicates that the odds are $1 : 1000$ for this bet. Is this an accurate description?