The mean cost of textbooks for one class is greater than $14…

Questions

The meаn cоst оf textbоoks for one clаss is greаter than $140. Identify the type I and type II errors for the hypothesis test of this claim.

DIRECTIONS: Chооse the best аnswer fоr eаch question. The World's Fаvorite Drug [A] It's 1:45 a.m., and 21-year-old Thomas Murphy is burning the midnight oil, studying for an important engineering exam he has at 2:00 in the afternoon later today. To stay awake and alert, he's had two cups of coffee in the last three hours and is now downing a popular energy drink - one that has two to three times the amount of caffeine as a similar sized can of soda. Many students like Murphy, as well as marathon runners, airline pilots, and long-distance travelers, owe their energy to one of humankind's oldest stimulants: caffeine.[B] The power to counter physical fatigue and increase alertness is part of the reason caffeine ranks as the world's most popular mood-altering drug. It is found not only in sodas, energy drinks, coffee, and tea, but in diet pills, pain relievers (like aspirin), and chocolate bars. Many societies around the world have also created entire rituals around the use of caffeine. For example, there's the cafe culture of France, the tea ceremony in Japan, and the morning cup of coffee or tea that marks the start of the day in many cultures.[C] Caffeine is present in many of the foods and drinks we consume, but is it good for us? Charles Czeisler, a scientist and sleep expert at Harvard Medical School, believes that caffeine causes us to lose sleep, which he says is unhealthy. "Without adequate sleep - the typical eight hours - the human body will not function at its best, physically, mentally, or emotionally." Too often, Czeisler says, we consume caffeine to stay awake, which later makes it impossible for us to get the rest we need.[D] Health risks have also been tied to caffeine consumption. Over the years, studies have attributed higher rates of certain types of cancer and bone disease to caffeine consumption. To date, however, there is no proof that caffeine actually causes these diseases.[E] A number of scientists, including Roland Griffiths - a professor at the Johns Hopkins School of Medicine in the United States - believe that regular caffeine use causes physical dependence. Heavy caffeine users, Griffiths says, exhibit similar behaviors. For example, their moods fluctuate from high to low, they get mild to severe headaches, or they feel tired or sad when they can't have a caffeinated drink. To minimize or stop these feelings, users must consume caffeine - a behavior Griffiths says is characteristic of drug addiction.[F] Despite these concerns, the general opinion in the scientific community is that caffeine is not dangerous when consumed in moderation. This means having one or two small cups of coffee (about 300 milligrams of caffeine) per day, for example. Furthermore, a lot of current research contradicts long-held negative beliefs about caffeine, and suggests that it may, in fact, have health benefits. For instance, studies have shown that caffeine can help ease muscle pain. Because it is a stimulant, caffeine can also help improve one's mood. Research has also shown that some caffeinated drinks - specifically certain teas - have disease-fighting chemicals that can help the body fight a number of illnesses, including certain types of cancer.[G] In addition, as a type of mental stimulant, caffeine increases alertness, memory, and reaction speed. Because it fights fatigue, it facilitates performance on tasks like driving, flying, and solving simple math problems. And while it is true that caffeine can increase blood pressure, the effect is usually temporary and therefore not likely to cause heart trouble. This is especially true if caffeine is consumed in moderation. Moreover, despite its nearly universal use, caffeine has rarely been abused. "With caffeine, overuse tends to stop itself," says Jack Bergman, a specialist at Harvard Medical School. If you consume too much, "you get ... uncomfortable, and you don't want to continue."[H] Caffeine's behavioral effects are real, but most often mild. Getting that burst of energy, of course, is why many of the world's most popular drinks contain caffeine. Whether it's a student drinking coffee before class or a businessperson enjoying tea with lunch, humankind's favorite stimulant is at work every day, all over the world.According to the passage, which is the best summary of the general medical opinion about caffeine and health?

DIRECTIONS: Reаd the pаssаge. Cоmplete the chart with wоrds frоm the passage. Being Realistic About Video Games [A] The debate about the effects of video games on children and teenagers will probably never come to an end. For every person who argues that video games are no different from movies, television, or other visual forms of entertainment, there is another who argues that video games are an especially negative force for young people at a crucial stage of their development. As a result of these polarized1 opinions, it is difficult for people to know what the truth is. However, according to the research of experts who study the effects of video games, both sides of the debate are partially right. It is clear that video games can have both positive and negative effects on the young people who play them.[B] In recent years, several studies within the field of psychology have demonstrated that video games are able to benefit young people if played in moderation. Video games are fun and stimulating and, in turn, are able to maintain a young person's concentration for a longer period of time than other media. As a result, if there is something to be learned through the gaming experience (for example, information about a new geographical location), the video game can facilitate the growth of a young person's knowledge.[C] Interestingly, researchers have also learned that video games can help children and teenagers develop several skills that can be transferred to other areas of their life, including education. Fast-moving video games have been shown to improve reaction speed, hand-eye coordination, as well as the ability to recognize patterns. Because they also involve puzzles and the need for strategy, video games have also been linked with improved problem-solving skills. Finally, although some have suggested that video gamers often exhibit signs of loneliness, research has demonstrated that modern online video games have helped develop social skills, including team building and cooperation. [D] Despite these many benefits, however, one cannot ignore the fact that video games can have a highly negative effect on some children and teenagers. This is typically the case for those young people who are addicted to video games and, thus, play them excessively. [E] The first major downside of excessive video game playing is the negative effect it has on academic achievement. Research has made it clear that there is a direct correlation between the amount of time a young person spends playing video games and their performance in school. Quite simply, those who play more tend to receive lower grades. In one study, for instance, it was demonstrated that almost 50 percent of heavy gamers received poor test scores. This was much worse than the 25 percent of light gamers who also did poorly on their tests.[F] Much like television and Internet addiction, young people who become dependent on video games are also more likely to suffer from physical health problems. While some children and teenagers become obese2 from a lack of exercise, others develop constant fatigue due to a lack of sleep.[G] Based on the pros and cons discussed in this article, it should be clear to parents and guardians that there is no black and white answer to the question of whether video games are a positive or negative force for young people. While video games can facilitate the development of important skills, too much time on the screen can lead to severe negative side effects and even cancel out the benefits. Consequently, parents and guardians ought to focus on finding the right balance between too much gaming and no gaming at all.1 If an issue is polarized, there are different groups holding opposite opinions about it.2 If someone is obese, they are overweight to an unhealthy level. Positive Effects Negative Effects •  helps to 1________ the growth of a young person's knowledge •  fast-moving video games help to improve reaction speed, 2________ coordination, and pattern recognition •  online games help to develop 3________ skills •  young people who play more tend to get 4________ grades •  some young people develop physical health problems, including obesity and 5________ (5) _________________