Exam 11: Inductive Reasoning

Make this inductive (statistical)syllogism into a relatively strong argument by supplying an appropriate premise or conclusion:Greg must be into all that New Age stuff since he wears his hair in a ponytail.

Evaluate the following argument in accordance with the criteria discussed in the text. If you don't want your kids to smoke tobacco,keep them away from marijuana.It has been estimated that 75 percent of pot smokers do use other drugs,including tobacco.

Consider the following passage: Julia sells exotic birds.She has placed four orders with wholesale bird supplier Papagayo Co. ,and all of them have been filled with healthy birds.Lately,however,some wholesale competitors have been trying to get her to order from them.But,when it's time to make the next order,she decides she's better off with Papagayo because she's pretty sure she'll get healthy birds.(Do not assume that you know anything about birds or the bird business. ) The attribute of interest here is

According to Department of Transportation statistics for 2005:1% of drivers received a citation for a moving violation;40% of them were under 30 years old.Which of the following conclusions (about 2005)CANNOT be deduced from this information? Explain your answer in no less than a half a page,and no more than one page. 1.99% of drivers did not receive a citation for a moving violation. 2.60% of those who received a citation for a moving violation were 30 or older. 3.60% of those who did not receive a citation for a moving violation were under 30. 4.60% of drivers under 30 years old received a citation for a moving violation. 5.A cousin who is under 30 is more likely to get a citation for a moving violation than is a cousin who is 30 or older.

Evaluate the following analogical argument: Washburn has read that it is good to include cabbage in one's diet.He doesn't care much for cabbage,but he likes brussels sprouts.Since the latter look like small cabbages,he assumes that their nutritional benefits will be about the same as those of cabbage.

Johnson is hired by a company to see if a new product,Topocal,will cause hair to grow on the heads of bald men.He recruits one thousand bald men,and randomly divides them into two groups:Five hundred (group A)rub Topocal on their scalps each day;the other five hundred (group B)rub a standard skin lotion on their scalps each day.After two months,Johnson checks to see what the results have been.He finds that there has been hair growth in 7 percent of group A and in 2 percent of group B.What is the population?

Evaluate the following argument in accordance with the criteria discussed in the text. Raphael is troubled by the fact that when he purchases new guitar strings,they seem always to go dead after just a few weeks of use.A friend suggests that he boil the strings in vinegar when they lose their resonance.Raphael tries it,and the strings sound almost like new again.After a few weeks,the strings go dead again,and Raphael boils them in vinegar and gets the same results.He resigns himself to a session with boiling vinegar every few weeks.

Evaluate the following argument in accordance with the criteria discussed in the text. "I'm over seventy years old and got all of my natural teeth but one.The secret is to eat a dollop of raw veal bone marrow every day." -Attributed to Mrs.Keller [a "wise old woman of Ohio"] by Robert L.Tubbesing,Old Farmer's Almanac (1986)

Critically discuss the following analogical argument: Economic sanctions simply do not work.As a weapon of international persuasion,they are about as effective as popguns. The United Nations imposed drastic sanctions upon Rhodesia;they failed utterly. We imposed sanctions upon Poland;nothing happened. Our government has forbidden trade with Cuba for the past twenty-five years;Cuba goes its own way.Most recently,the president has laid heavy sanctions upon Libya;our noble allies have pooh-poohed the effort. You can count on the same kind of result if economic sanctions are imposed on North Korea.

Evaluate the following argument in accordance with the criteria discussed in the text. A lottery winner,asked why he thought he had won a major prize,pulled a small rhinestone four-leaf clover out of his pocket and said,"I think this had a lot to do with it."

Make this inductive (statistical)syllogism into a relatively strong argument by supplying an appropriate premise or conclusion:A vast number of people who care about sustainability have a vegetable garden,so Scott probably does,too.

Juanita has taken six courses at Valley Community College,and she has a grade average of B so far.All the courses she has taken have been in sociology and psychology.She's thinking of enrolling in another course next term,and she expects to make at least a B in whatever she takes.If we don't know yet what subject she will take,would her argument be stronger,weaker,or neither if her previous six courses had been in four different subjects rather than two?

"An FBI study of thirty-five serial killers [killers of several people,not all at once] revealed that twenty-nine were attracted to pornography and incorporated it into their sexual activity,which included serial rape and murder." This assertion,taken from an antipornography ad,seems to have been intended to show that pornography is a causal factor of serial rape and murder.Does it show that?

A)Provide an informal analysis of the following passage;or B)in analyzing the passage,do the following: a.Identify the causal hypothesis at issue. b.Identify what kind of study it is. c.Describe the control and experimental groups. d.State the difference in effect (or cause)between control and experimental groups. e.Identify any problems in either the study or the report of it,including but not necessarily limited to uncontrolled variables. f.State the conclusion you think is warranted by the report. BOSTON-AP,UPI reports (adapted).The constant bright lights of hospital nurseries,often two to four times as bright as normal office lighting,may contribute to the blinding of hundreds of premature babies each year,a recent study warns.Doctors kept track of the incidence of retinopathy,a disease of the retina,in two groups of premature babies.One group was kept in incubators covered with acetate that reduced the amount of light by 58 percent.The rest stayed in ordinary incubators.Among the smallest babies,the researchers found that twenty-one of thirty-nine (54 percent)in shielded incubators developed retinopathy,compared with eighteen of twenty-one (86 percent)of those exposed to the bright lights.Dr.Penny Glass,a developmental psychologist at Children's Hospital National Medical Center and Georgetown University Medical Center,who directed the study,recommends that the light levels in hospital nurseries be brought down."I feel that the increase in light levels has not been demonstrated safe," she said.

Evaluate the following argument in accordance with the criteria discussed in the text. Cheryl and her new acquaintance,Ted,have just walked into Target when in comes her steady boyfriend,Lemmy."Oh,for crying out loud," Cheryl thinks."Why would he come into Target,of all places? I must be being punished for something I did,and I know what."

When we say that the number is "statistically significant," which of these is closest to what we mean?

Evaluate the following analogical argument: Hank Kingscote has won every one of his fifteen previous prizefights by knockouts.The chances are that the poor fellow who's going to fight him next will wind up stretched out on the canvas.

Make this inductive (statistical)syllogism into a relatively strong argument by supplying an appropriate premise or conclusion:Dennis plays trumpet in the marching band at Yale,so he probably doesn't have a girlfriend.

Analyze the following study according to the criteria set by your instructor: Smoking greatly increases the likelihood of premature facial wrinkling,according to University of Utah scientists reporting in the Annals of Internal Medicine.The scientists studied 109 smokers and 23 people who had never smoked,all between the ages of thirty-five and fifty-nine.The smokers had smoked three to fifty pack-years,with a pack-year equal to smoking one pack a day per year.Each subject estimated the number of hours spent in the sun,and that information was adjusted for pigmentation,place of residence,and use of sunscreen or protective clothing.The subjects' temples were then photographed and the pictures evaluated by two doctors,who did not know whether the subject smoked or not.The reviewers agreed on the degree of wrinkling 81 percent of the time,and disagreements were averaged.The results were adjusted for age and pigmentation.Heavy smokers were nearly five times more likely to show excessive skin wrinkling than their nonsmoking counterparts. -Adapted from Science News and AP reports

Evaluate the following argument in accordance with the criteria discussed in the text. The car usually makes it over the hills between here and the lake without any trouble.The only time it makes any trouble is when we have to pull the boat and trailer;they must make too heavy a load for the car's small engine.