91影视

Odds. In Exercises 41鈥�44, answer the given questions that involve odds.

Relative Risk and Odds Ratio In a clinical trial of 2103 subjects treated with Nasonex, 26 reported headaches. In a control group of 1671 subjects given a placebo, 22 reported headaches. Denoting the proportion of headaches in the treatment group by $p_t$and denoting the proportion of headaches in the control (placebo) group by role="math" localid="1644405830274" $p_c$, the relative risk is $\frac{p_t}{p_c}$. The relative risk is a measure of the strength of the effect of the Nasonex treatment. Another such measure is the odds ratio, which is the ratio of the odds in favor of a headache for the treatment group to the odds in favor of a headache for the control (placebo) group, found by evaluating the following:$\frac{p_t/\left(1-p_t\right)}{p_c/\left(1-p_c\right)}$

The relative risk and odds ratios are commonly used in medicine and epidemiological studies. Find the relative risk and odds ratio for the headache data. What do the results suggest about the risk of a headache from the Nasonex treatment?

Identifying Probability Values Which of the following are probabilities?

0 3/5 5/3 -0.25 250% 7:3 1 50-50 5:1 0.135 2.017

At Least One. In Exercises 5鈥�12, find the probability.

Three Girls Find the probability that when a couple has three children, at least one of them is a girl. (Assume that boys and girls are equally likely.)

Finding Complements. In Exercises 5鈥�8, find the indicated complements.

LOL A U.S. Cellular survey of smartphone users showed that 26% of respondents answered 鈥測es鈥� when asked if abbreviations (such as LOL) are annoying when texting. What is the probability of randomly selecting a smartphone user and getting a response other than 鈥測es鈥�?

Penicillin 鈥淲ho discovered penicillin: Sean Penn, William Penn, Penn Jillette, Alexander Fleming, or Louis Pasteur?鈥� If you make a random guess for the answer to that question, what is the probability that your answer is the correct answer of Alexander Fleming?

In Exercises 6鈥�10, use the following results from tests of an experiment to test the effectiveness of an experimental vaccine for children (based on data from USA Today). Express all probabilities in decimal form.

If 1 of the 1602 subjects is randomly selected, find the probability of getting 1 that developed flu.

Finding Complements. In Exercises 5鈥�8, find the indicated complements.

Flights According to the Bureau of Transportation, 80.3% of American Airlines flights arrive on time. What is the probability of randomly selecting an American Airlines flight that does not arrive on time?

At Least One. In Exercises 5鈥�12, find the probability.

Probability of a Girl Assuming that boys and girls are equally likely, find the probability of a couple having a boy when their third child is born, given that the first two children were both girls.

In Exercises 5鈥�36, express all probabilities as fractions.

Social Security Numbers A Social Security number consists of nine digits in a particular order, and repetition of digits is allowed. After seeing the last four digits printed on a receipt, if you randomly select the other digits, what is the probability of getting the correct Social Security number of the person who was given the receipt?

In Exercises 6鈥�10, use the following results from tests of an experiment to test the effectiveness of an experimental vaccine for children (based on data from USA Today). Express all probabilities in decimal form.

If 1 of the 1602 subjects is randomly selected, find the probability of getting 1 who had the vaccine treatment or developed flu.