Statistical Probability

A controversial but promising new cancer treatment uses the HIV virus to attack Leukemia cells. To investigate the claimed effect of an injection containing a modified version ofthe HIV virus, a health researcher obtains 300 adults with late stage liver cancer volunteer for the study after receiving the prognosis that no FDA approved treatment would be effective. Each of the subjects is then randomly assigned to get one series of injections from among two possible: Either the 'modified HIV virus' or else a 'fake HIV virus' an injection that looks the same but does not contain any modified HIV. The subjects did not know which of the two treatments they were assigned to be treated with. After a series oftreatments, each subject is checked to see if the cancer has gone into remission, stayed the same or spread. The number of cancer affected cells is recorded before and after treatment. Question 3 of 8 Which ofthe following best describes the design ofthis study? 3 A blind survey :| An observational study :| A blind experiment :| An experiment 3 A survey :| A blind observational study A developmental psychologist travels toJamaica to study the effects of maternal THC use on cognitive behavioral outcomes of infants. Moms are placed into groups depending on their THC use: habitual, moderate, no use. In order to assess the the three levels ofTHC use, the program selects a random sample of 600 moms who responded to the online survey and classified them according to the THC use they indicated. Five years later, the study finds that 8% ofthose who indicated habitual THC use showed developmental delays, 10% of those who indicated moderate THC use showed developmental delays and 12% ofthose who indicated no THC use showed developmental delays. Question 1 of8 Which ofthe following is the correct design ofthis study? :| A randomized observational study :| A randomized experiment :| A randomized response study :| A randomized experiment :| A blind observational study :| An observational study Question 2 of 8 In this case, can we conclude that any association that is found in the sample was due to causation? In other words, can we conclude that maternal THC use is the cause for whether or not the sampled children displayed developmental delays? :| No, because association never implies causation :| Yes, because of the relatively large sample size (n=600). :| Yes, since the sample was random :| No, since the individuals chose themselves which THC condition they would be in they were not randomly assigned. :| Yes, since the individuals were randomly assigned to one ofthe the three THC treatments Question 6 of 8 A study was conducted to explore the effect of ethnicity (caucasian or other ethnic groups) on the getting hired. An identical job application was shown to a random sample of120 tech companies in Silicon Valley. The companies were randomly assigned to review an application with a white sounding name or an application with a black sounding name. The average number of callbacks for an onsite interview with the white sounding name was higher than the average number of callbacks for an onsite interview with the black sounding name. Complete the the following sentence: This Choose... ' is Choose... ' and Choose... ' a control group. Question 7 of 8 When designing and writing questions for a survey, which of the following are issues that you need to pay attention to? :| Random Sample :| ControlGroup :| Sensitive questions :| All of the above. :| None of the above Question 8 of 8 Which ofthe following would be the best question to include in a poll in order to assess the opinions of US. adults about unprotected sex? D Given the dangers of contracting potentially deadly sexually transmitted diseases from unprotected sex, which of the following best describes your view about unprotected sex? 0 Strongly Favor 0 Favor 0 Oppose 0 Strongly Oppose 0 Not Sure |:| Given the pleasurability of unprotected sex, which ofthe following best describes your view about unprotected sex? 0 Strongly Favor - Favor 0 Oppose 0 Strongly Oppose 0 Not Sure |:| Which of the following best describes your view about unprotected sex? 0 Strongly Favor 0 Favor 0 Oppose 0 Strongly Oppose 0 Not Sure Question 4 of 8 lfthe number of cancer cells is really significantly lower on average in the 'HIV injection' group, can we reasonably conclude that the improved treatment of those in the 'HIV injection' group was actually caused by the HIV injection? :| Yes, because of the relatively large sample size (n=300). :| Yes, because this study has a control group. :| No, since the adults volunteered to participate in the study :| Yes, since the individuals were randomly assigned to a treatment using a 'modified HIV virus' or else a 'fake HIV virus'. :| No, because the individuals were randomly assigned to da treatment using a 'modified HIV virus' or else a 'fake HIV virus'. :| No, since the adults volunteered to participate in the study :| No, because the subjects didn't know whether they were treated using a 'modifled HIV virus' or else a 'fake HIV virus'. Question 5 of 8 A study explored the relationship between spelling bee performance and vocabulary size. The researchers followed a group of children who are 'expert spellers' and a group of children who are 'novice spellers' and found a larger vocabulary among those who are 'expert spellers'. After the researchers collected more data, they discovered that the time studying words from the dictionary was significantly higher, on average, in the 'expert spellers' group. Which ofthe following is true? :| Study time is a lurking variable :| Study time is an explanatory variable :| Study time is a response variable :| None of the above