When an individual is exposed to radiation, death may ensue. Factors affecting the outcome are the size of the dose, the length and intensity of the exposure, and the biological makeup of the individual. The term LDso is used to denote the dose that is usually lethal for 50% of the individuals exposed to it. Assume that in a nuclear accident 30% of the workers are exposed to the LDso and die; 40% of the workers die; and 68% are exposed to the LDs or die. What is the probability that a randomly selected worker is exposed to the LD_n? Use a Venn diagram to find the probability that a randomly selected worker is exposed to the LDso but does not die. Find the probability that a randomly selected worker is not exposed to the LDso but dies.

When an individual is exposed to radiation, death may ensue. Factors affecting the outcome are the size of the dose, the length and intensity of the exposure, and the biological makeup of the individual. The term LDso is used to denote the dose that is usually lethal for 50% of the individuals exposed to it. Assume that in a nuclear accident 30% of the workers are exposed to the LDso and die; 40% of the workers die; and 68% are exposed to the LDs or die. What is the probability that a randomly selected worker is exposed to the LD_n? Use a Venn diagram to find the probability that a randomly selected worker is exposed to the LDso but does not die. Find the probability that a randomly selected worker is not exposed to the LDso but dies.

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

ie 19. A certain drug is claimed to be effective in curing colds. In an experiment on 164 people with cold, half of them were given the drug and half of them given sugar pills. The patient's reactions to the treatment are recorded in the following table : Helped Harmed No effect Total 52 10 20 82 Drug 44 12 26 82 Sugar pills Total 96 22 46 164 On the basis of this data, can it be concluded that there is significant difference in the effect cs the drug and sugar pills ? (For v = 2 x0os = 5.99) 0.05
1. Observational studies suggest that moderate use of alcohol reduces heart attacks, and that red wine may have special benefits. One reason may be that red wine contains polyphenols, substances that do good things to cholesterol in the blood and so may reduce the risk of heart attacks. In an experiment, healthy men were assigned at random to drink half a bottle of either red or white wine each day for two weeks. The level of polyphenols in their blood was measured before and after the two week period. Here are the percent changes in level for the subjects in both groups.Red 3.5 8.1 7.4 4.0 0.7 4.9 8.4 7.0 5.5White 3.1 0.5 -3.8 4.1 -0.6 2.7 1.9 -5.9 0.1 a. Is there good evidence that red wine drinkers gain more polyphenols on average than white wine drinkers? b. Does this study give reason to think that it is drinking red wine, rather than some lurking variable, that causes the increase in blood polyphenols? Justify your answer.c. Calculate and interpret a 95% confidence interval for…
2. The drug Ritalin is designed to stimulate the central nervous system. In a random sample of 242 boys aged ten - twelve years old, it was found that 68 of the boys were taking Ritalin. It is known that the proportion of all boys aged 13 - 15 who take Ritalin is 22%. A researcher claims that the population proportions of boys who take Ritalin aged 10 – 12 is different than boys aged 13 - 15. Can you support this claim at the 5% significance level? a. Conduct a hypothesis test to test the claim at the 5% significance level. Be sure to state you Ho and Ha, your test statistic and p-value, whether or not you reject Ho and whether you support the claim. b. Write a complete sentence describing what a Type I error is in context. c. Write a complete sentence describing what a Type II error is in context.
1. A recent report on elementary schools in Tarrant county claimed that 13% of elementary students typically walk to school. Luka thinks that the proportion is different than 0.13 at his large elementary school. Luka surveys a random sample of 80 students from his school and finds that 17 typically walk to school. Do the data provide convincing evidence that Luka's school has a different proportion of walkers than claimed by the report? Use a = 0.01.
A medical researcher wishes to determine if a pill has the undesirable side effect of reducing the blood pressure of the user. The study involves recording the initial blood pressures of 15 college-age women. Suppose the data are normally distributed. After they use the pill regularly for six months, their blood pressure are again recorded. The data is given bellow. Subject 1 2 3 4 5 6 7 8 Before 70 80 72 76 76 76 72 78 9 10 11 12 13 14 15 82 64 74 92 74 68 84 64 72 74 60 74 72 74 After 68 72 62 70 58 66 68 52 (a) Calculate a 95% confidence interval for the mean reduction in blood pressure. (b) Does the data support a claim that use if the pill can reduces blood pressureby using one- tailed test at level a = 0.01. If we choose level 0.001 in part (b), what can you conclude.
A. Headache Pain : There are many over-the-counter pain relievers. By the end of the semester, you have a tremendous headache and are looking for the most effective pain relief available. You conduct a study comparing the three most popular pain relievers and a placebo to see which work best. You use only subjects with headaches and record the amount of time (in minutes) it takes for their headache to go away after they receive the medication. You randomly assign 60 participants to one of the four conditions using a double- + blind procedure. (Use a = Placebo 70 Drug A 30 Drug B 10 Drug C 10 30 60 40 20 50 40 10 10 60 30 40 10 10 40 30 30 30 30 30 10 40 20 20 20 60 40 20 30 50 30 30 10 30 30 20 20 60 20 10 10 20 40 20 30 20 50 20 10 40 20 30 30 State the hypotheses Critical value and df Test statistic
A. Headache Pain : There are many over-the-counter pain relievers. By the end of the semester, you have a tremendous headache and are looking for the most effective pain relief available. You conduct a study comparing the three most popular pain relievers and a placebo to see which work best. You use only subjects with headaches and record the amount of time (in minutes) it takes for their headache to go away after they receive the medication. You randomly assign 60 participants to one of the four conditions using a double- blind procedure. (Use a = .05) Drug A Drug C 10 Placebo Drug B 10 70 30 30 60 40 20 50 40 10 10 60 30 10 10 40 40 30 30 30 30 30 10 40 20 20 20 60 40 20 30 50 30 30 10 30 30 20 20 60 20 10 10 20 40 30 20 50 20 20 10 40 20 30 30 IV (or predictor) variable DV (or criterion) variable What type of analysis should you conduct to determine which method relieves headache pain most swiftly?
1.76 Peace Corps Volunteers. The Peace Corps is an indepen- dent U.S. government agency that provides trained volunteers for countries requesting assistance. According to Peacecorps.org, as of September 2012, volunteers currently serve in about 76 different host countries. The average age of a volunteer is about 28 years old. The following table reports the percentage of total volunteers serving by geographic region. Percent of volunteers Region Africa 43% Latin America 21% Eastern Europe/Central Asia 15% Asia 10% Caribbean 4% North Africa/Middle East 4% Pacific Islands 3% a. Use the table to design a procedure for obtaining a stratified sam- ple (with proportional allocation) of 50 Peace Corps volunteers. b. If stratified random sampling with proportional allocation is used to select the sample of 50 Peace Corps volunteers, how many would be selected from the Caribbean?
A common cause factor that would affect both attendance at the beach and ice cream sales at the beach would be: 1.day of the week 2.cost of ice cream 3.weather 4.sales of bathing suits
3. Scenario It is believed that large doses of acetaminophen (the active ingredient in over the counter pain relievers like Tylenol) may cause damage to the liver in nearly half of those tested. A researcher wants to conduct a study to estimate if the proportion of acetaminophen users who have liver damage is the same as previously reported. For participating in this study, he will pay each subject $20 and provide a free medical consultation if the patient has liver damage. Part A If he wants to limit the margin of error of his 98% conﬁdence interval to 2%, what is the minimum number of subjects he needs? (answer should be in the form of x,xxx) the minimum amount of money he needs to set aside to pay his subjects? $ (answer should be in the form of $xx,xxx) Part B The amount you calculated in Part A is substantially over his budget so he decides to use fewer subjects. Will this change increase or decrease the width of his conﬁdence interval? Will this new confidence interval be…
The price per share of stock for a sample of 25 companies was recorded at the beginning of the first financial quarter and then again at the end of the first financial quarter. How stocks perform during the first financial quarter is an indicator of what is ahead for the stock market and the economy. Company End of 1st quarter Beginning of 1st quarter Bank of New York Mellon 54.19 53.82 Kraft Foods 55.70 77.02 E.I. du Pont de Nemours and Company 102.57 109.00 Consolidated Edison 79.95 83.58 Johnson & Johnson 126.01 139.23 Union Pacific 132.73 135.78 Comcast 32.06 41.07 Applied Materials 50.91 53.04 Pfizer 35.40 36.44 General Electric 14.05 17.98 AT&T 32.54 38.54 Cisco Systems 44.83 38.86 Home Depot 184.63 188.03 JP Morgan Chase 108.78 107.95 Procter & Gamble 71.96 90.65 Verizon 48.82 53.53 Devon Energy 36.20 42.23 Lilly 79.07 84.68 Microsoft 95.00 85.95 Coca Cola 42.59 45.59 Qualcomm 50.82 65.20 Exxon Mobil Corporation 76.95…