Show your work. (c) What is the probability that a person has the antibody given that the EIA test is positive? Respondent Robotics: Simulating responses to Likert-scale survey items. So if, for example, a survey is distributed to 1000 people and 200 of them complete it, then the survey response rate would be 20%. Preparing for the GMAT A company that offers courses to prepare students for the Graduate Management Admission Test (GMAT) has the following information about its customers: 20% are currently undergraduate students in business; 15% are undergraduate students in other fields of study; 60% are college graduates who are currently employed; and 5% are college graduates who are not employed. (a) Who are the individuals? Justify your answer. Then find $P(J \text { and } R)$(d) Explain why $P(J \text { or } R) \neq P(J)+P(R) .$ Then use the general addition rule to compute $P\left(\int \text { or } R\right)$. Compared to students who did not experience a change in instructional mode during the pandemic, those who shifted from all in-person to all on-line were much less likely: In addition, the majority of returning students who previouslylearned mostly or completely in-person and then transitioned to a partially or fully on-line experience in the fall believed that the quality of their education declined. Probability models? We need 2 cookies to store this setting. Get rich Refer to Exercise 63. Together with researchers Kai Rune Larsen and yvind L. Martinsen, Jan Ketil Arnulf has demonstrated this possibility in a research article that was recently published in the periodical Sage Open. Find the probability that the student uses MySpace regularly. 10 days ago, Posted Find the probability that the student uses YouTube regularly. Rolling a die The following figure displays several possible probability models for rolling a die. (c) What is the probability that a Canadian's mother tongue is a language other than English or French? We use cookies to let us know when you visit our websites, how you interact with us, to enrich your user experience, and to customize your relationship with our website. Sampling senators The two-way table describes the members of the U.S. Senate in a recent year. Here are approximate probabilities of positive and negative EIA outcomes when the blood tested does and does not actually contain antibodies to HIV:22 Suppose that 1% of a large population carries anti- bodies to HIV in their blood. Respondent Relationships: If potential respondents have a relationship with a brand or organisation they are far more likely to respond to a survey request. We actually need to ask ourselves whether the numerous employee surveys being conducted regularly actually measure what they claim to, says Arnulf. It is particularly common among people of African and Asian ancestry. To be thriving in their personal well-being (27% vs. 45%), To strongly agree that a professor cared about them as a person (25% vs. 65%), To strongly agree that they had a mentor (17% vs. 41%). (c) The probability of being dealt 5 spades is the product of the five probabilities you have found.Why? One of these criteria is the surveysmargin of error. You can check these in your browser security settings. Justify your answer. A recent survey suggests that 85% of college students have posted a profile on Facebook, 73% use YouTube regularly, and 66% do both. (a) What percent of calls result in a contribution? Get rich A survey of 4826 randomly selected young adults (aged 19 to 25) asked, What do you think are the chances you will have much more than a middle-class income at age 30? Explain your method. (b) What percent of people who are lactose intolerant are Asian? It is a subsidiary of The Pew Charitable Trusts. Income tax returns Here is the distribution of the adjusted gross income (in thousands of dollars)reported on individual federal income tax returns in a recent year:(a) What is the probability that a randomly chosen return shows an adjusted gross income of $\$ 50,000$ or more? Find and create gamified quizzes, lessons, presentations, and flashcards for students, employees, and everyone else. Let's say our hypothetical survey asks a yes or no question about whether the economy should be the top concern of the country's political leaders. (b) What is the conditional probability that a student is studying Spanish given that he or she is studyingsome language other than English? Despite widespread speculation and anecdotal claims about the disruptions and negative impacts of the Covid-19 pandemic on the quality of a college education, a new national survey reveals that the majority of students still rated their educational experiences this fall asexcellent or very good.. An inspector draws2 switches at random, one after the other. 71. Brand Recognition: Surveys distributed by well-known, recognized brands tend to attract better response rates than those carried out by unknown organisations. Sage Open, January-March, 1-18. doi:10.1177/2158244018764803.This article was first published in the online paper forskning.no 29 May 2018. Suppose we select a student at random. Theyve struggled, but persisted. Who eats breakfast? (c) What is the probability that the first two tosses are not doubles and the third toss is doubles? }}\end{array}$$, In a table of random digits such as Table D, each digit is equally likely to be any of $0,1,2,3,4,5,6,$$7,8,$ or $9 .$ What is the probability that a digit in the table is 7 or greater?$$\begin{array}{l}{\text { (a) } 7 / 10 \quad \text { (c) } 4 / 10 \quad \text { (e) } 1 / 10} \\ {\text { (b) } 6 / 10 \quad \text { (d) } 3 / 10}\end{array}$$, Twenty of a sample of 275 students say they are vegetarians. Does it take longer to learn in thewinter, when babies are often bundled in clothes that restrict their movement? Since these providers may collect personal data like your IP address we allow you to block them here. Choose a Canadian at random and ask, What is your mother tongue?. P(B) + P(E). Often, two questions will be enough to guess the answer to a third question. Suppose we select a college student at random and learn that the student has a profile on Facebook. In surveys with multiple questions on the same topic, patterns of similarities occur which will determine the statistics in the answers. Why? Lactose intolerance Lactose intolerance causes difficulty in digesting dairy products that contain lactose(milk sugar). (c) Deal a card from a shuffled deck: P(clubs) = 12/52, P(diamonds) = 12/52, P(hearts) = 12/52, Languages in Canada Canada has two official languages, English and French. Moving from in-person to on-line instruction had several negative effects. They go back to earlier tabletop games such as Dungeons & Dragons. Find the probability that the student uses YouTube regularly. Snapsolve any problem by taking a picture. Refer to Exercise 68. If 51% of all respondents say yes, we would estimate the true population value to fall between 48% and 54%. \text { (b) } 0.32 \text { (c) 0.16. You can disable cookies at any time within your browser settings. To better appreciate the problem, consider these three recent news headlines: Each headline includes the word majority. But take a moment to consider the wide variation in the survey data thats actually being cited in each of the stories above. Overall ratings. Suppose a candy maker offers a special Gump box with 20 chocolate candies thatlook the same. Choose a Canadianat random and ask, What is your mother tongue? Illegal music downloading has become a big problem: 29% of Internet users download music files, and 67% of downloaders say they dont care if the music is copyrighted.15 What percentof Internet users download music and dont care if its copyrighted? A recent survey suggests that 85% of college students have posted a profile on Facebook, 73% use YouTube regularly and 66 do both, suppose we select a college student at random find the probability that the randomly selected college student has posted a profile on Facebook or uses YouTube regularly. Suppose we select a college student at random. Medical risks Morriss kidneys are failing, and he is awaiting a kidney transplant. Late shows Some TV shows begin after their scheduled times when earlier programs run late.According to a networks records, about 3% of its shows start late. Show your work. Otherwise you will be prompted again when opening a new browser window or new a tab. Suppose that a college student is selected at random. (a) What is the probability that the college student has posted a profile on Facebook or uses YouTube regularly? In a recent month, 88% of automobile drivers filled their vehicles with regular gasoline, 2%purchased midgrade gas, and 10% bought premium gas.17 Of those who bought regular gas, 28% paid with a credit card; of customers who bought midgrade and premium gas, 34% and 42%, respectively, paid with a credit card. Pew Research Center does not take policy positions. Many students forced online are displeased with the quality of their schooling and unhappy about their lives.. And in the third article, a majority of Americans refers to 51%. (b) If we select a U.S. senator at random, whats the probability that we choosea Democrat? If the second serve is also out, the player loses the point. Show your work. Aboutone-third of currently enrolled studentssaid they had considered stopping taking courses in the past six months (38% of associate degree students and 33% of baccalaureate students), andabout half of students (56% for associates students and 49% for bachelors students) said its likely or very likely the pandemic could impact their ability to continue their studies. Suppose we select a senator at random. You never know whatyoure gonna get. (a) $8 / 275=0.03$(b) $20 / 275=0.07$(c) $8 / 20=0.4$(d) 0.5(e) 1, The casino game craps is based on rolling two dice. Age of students and type of college. Professor and management researcher Jan Ketil Arnulf at BI Norwegian Business School is not at all sure that we can. Suppose we select a college student at random. (c) Consider the event that the randomly selected college student has posted a profile on at least one of these two sites. Suppose we select a senator at random. Suppose we select a student at random from among those who were part of the census and learn that the student mainly uses a Mac. Now, Arnulf is claiming that the management researchers use of surveys simply does not measure up. Make a Two-way table for the chance properties. The following is a two-way table for the given problem: A Venn diagram is a visual representation of relationships between things or limited groups of objects using circles. Researchers conducted anexperiment involving 250 patients with a medical condition and 750 other patients who did not havethe medical condition. (b) Find P(F | D). What is the probability that a randomly selected student uses YouTube regularly given that they have a Facebook profile. In Norway, the term leadership has been with us for seventy years. Universal blood donors People with type O-negative blood are universal donors. We often have to tick boxes indicating to what degree we agree with various statements. Tossing coins Refer to Exercise 40. Black and Hispanic students (60%) at two-year colleges were more likely than white students (52%) to question whether they will continue college because of the pandemic. Show your work. MySpace versus Facebook A recent survey suggests that 85% of college students have posted a profile on Facebook, 54% use MySpace regularly, and 42% do both. An article published in April 2018 determined that the average survey response rate was around 33%, but it acknowledged that there are many influencing factors. Remember that a deckcontains 52 cards, 13 of each suit, and that when the deck is well shuffled, each card dealt is equally likely to be any of those that remain in the deck. Explain what this value means. Students in an urban school were curious about how many children regularly eat breakfast. To find the probability that its next four flights into LaGuardia Airport all arrive on time, can we multiply (0.85)(0.85)(0.85)(0.85)? Can we then trust the management researchers findings? What Survey Response Rate Should I Expect? (a) Roll a die and record the count of spots on the up-face: $P(1)=0, P(2)=1 / 6, P(3)=1 / 3, P(4)=1 / 3,$$P(5)=1 / 6, P(6)=0$(b) Choose a college student at random and record gender and enrollment status: $P(\text { female full-time })=$ $0.56, P(\text { male full -time })=0.44, P(\text { female part-time })=$ $0.24, P(\text { male part-time })=0.17$(c) Deal a card from a shuffled deck: $P(\text { clubs })=$ $12 / 52, P$ (diamonds $)=12 / 52, P(\text { hearts })=12 / 52$ $P(\text { spades })=16 / 52$ . To know more check the Data were collected from parents who brought their babies to the University of Denver Infant Study Center to participate in one of a number of studies. (3) I am not free to decide how my daily work is organized. Hereis a two-way table of the responses for three levels of education:240 Is there an association between level of education and freedom to organize ones work? Together with colleagues Kai Rune Larsen, yvind L. Martinsen and Thore Egeland, Arnulf has also developed a method to see how correctly each person behaves with regard to semantics. In the first article, a majority of Canadians refers to 72%. As such, 51% in this survey would not necessarily translate to a "majority . If the first serve goes out of bounds, the player serves again. Surveys are widely used in the social sciences, perhaps especially within management research. What is the conditional probability that shehas two boys? Testing the test Are false positives too common in some medical tests? Students are devoting more time to academic preparation than they did over a decade ago. (a) Find $P(B | M)$ . (b) Find $P(R \cup F)$ . Since surveys only question asample of a larger populationthat is being studied whether that population is a single city, an entire country or something else the margin of error describes the estimated range within which we would expect the exact answer to fall. At the gym Suppose that 10% of adults belong to health clubs, and 40% of these health club membersgo to the club at least twice a week. Of the vegetarians, 9 eat both fish and eggs, 3 eat eggs but not fish, and 8 eat neither. (b) Consider the event that the randomly selected college student does not use MySpace regularly or has posted a profile on Facebook. Here is the distribution of results:(a) Whats the probability that the student is studying a language other than English? a female or someone who eats breakfast regularly? A survey response rate of 50% or higher should be considered excellent in most circumstances. Surveys detect both the interviewee's degree of agreement - what is referred to as attitude strength - and how the subjects understand and use language. A large medical trial assigned 1649 women to take either strontium ranelate or a placebo each day. 85 percent of Facebook users are on the platform. A survey response rate of 50% or higher should be considered excellent in most circumstances. The probabilityis 0.13 that the person chosen did not complete high school, 0.29 that the person has a high schooldiploma but no further education, and 0.30 that the person has at least a bachelors degree. Charitable Trusts lactose ( milk sugar ) it is particularly common among people of African a recent survey suggests that 85% of college students Asian ancestry the... Students in an urban School were curious about how many children regularly eat.! Be prompted again when opening a new browser window or new a tab has the given... 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