171Studies show that in 70 percent of traffic accidents, at least one driver involved is less than 10 miles from home when the accident occurs. This statistic¹ indicates that drivers have a tendency to drive incautiously when they are close to home, probably because familiar surroundings give them a false sense of security. Thus, the places where people feel safest are the places where they are in fact at greatest risk of serious injury.

172Copper occurs in nature mixed with other minerals and valuable metals in ore, and the proportion of copper² in the ore can vary considerably³. Until fairly recently, the only way to extract pure copper from ore was by using a process that requires large amounts of electric energy, especially if the proportion of copper in the ore is low. New copper-extracting technologies can use up to 40 percent less electricity than the older method to process the same amount of raw ore, especially when the proportion of copper in the ore is high. Therefore, we can expect the amount of electricity used by the copper-extraction industry to decline significantly.

173In measuring electrical activity in different parts of the brain, researchers found that people who describe themselves as generally happy have more activity in the left prefrontal lobe⁴ of their brains than do other people. Therefore, a medication for stimulating⁵ the left prefrontal lobe of the brain would be an effective treatment for clinical depression.

174The following appeared in a memo⁶ from a manager of a car dealership⁷.

"Ten years ago, long-term car leasing became available in our country of Mohilia as an alternative to outright⁸ car ownership, and leasing has steadily⁹ risen in popularity. For each of the last five years, the number of people leasing new cars has surpassed the number buying new cars. The average age of cars driven in Mohilia is six years; hence, if new car leases again outnumber purchases this year, it is likely that the majority of drivers will be driving leased, not individually owned, cars. Therefore, we should change the focus of our business from selling cars to leasing them."

175The following appeared in a newsletter about education policy.

'The average annual earnings¹⁰ of high school dropouts are significantly less than the average annual earnings of high school graduates. To address this problem, the state governor has proposed that the state should establish free vocational training programs for high school dropouts. But the availability of such programs would probably encourage some students who would otherwise have graduated to drop out in order to pursue vocational training. Hence the proposed programs would lower, not raise, the average earning potential of young people. Therefore, the state should not establish the vocational training programs but should instead focus on improving academic programs in our high schools.'

176The following appeared in a newsletter about health.

"The proportion of children in the United States who are overweight is greater now than ever before. Obesity¹¹ rates among children have been increasing since the 1970's and, during that same time period, the proportion of children living in suburbs has increased. Whereas children in rural areas tend to have outdoor active chores and children in cities often walk to school or other places they need to go, children in suburbs are typically driven everywhere. Thus the increase in childhood obesity is probably due mainly to the suburbanization¹² of America and the associated decrease in the opportunities children have for exercise."

177The following appeared as part of an article in a health and beauty magazine.

"A group of volunteers participated in a study of consumer responses to the new Luxess face cream. Every morning for a month, they washed their faces with mild soap and then applied¹³ Luxess. At the end of that month, most volunteers reported a marked improvement in the way their skin looked and felt. Thus it appears that Luxess is truly effective in improving the condition of facial skin."

178The cities of East Sacunda and West Sacunda are in an earthquake-prone area. Since 1985 both cities have had stringent¹⁴ building codes requiring all new buildings to have specific features designed to prevent damage in an earthquake. Buildings built before 1985 are exempt¹⁵ from the codes, but many building owners have modified their buildings to make them conform to the 1985 codes. Last year a major earthquake hit the area, and many people lost their homes. The number of people who were left homeless was much higher in East Sacunda than in West Sacunda, however, so we can conclude that building owners in East Sacunda were less likely to modify their buildings so as to bring them up to the 1985 code standards.

179The following appeared in a letter to the editor of an archaeological magazine.

"Archaeologists excavated¹⁶ a cave that had been inhabited by prehistoric¹⁷ people for thousands of years. These people hunted wild animals, many of whose bones were found at levels corresponding to different times of habitation. Most of the bones at the oldest levels, over 40,000 years old, were from a deer species whose modern-day descendants are known to prefer woodland habitats, whereas most of the bones at more recent levels, dating from 30,000 to 10,000 years ago, were from a gazelle species whose modern-day descendants are known to prefer grasslands¹⁹. We can thus conclude that the climate of the area changed dramatically between 40,000 and 30,000 years ago, causing the terrain²⁰ to change from woodland to grassland¹⁸."

180The following appeared in a magazine for the trucking industry.

"The Longhaul trucking company was concerned that its annual accident rate (the number of accidents per mile driven) was too high. It granted a significant pay increase to its drivers and increased its training standards. It also put strict limits on the number of hours per week each driver could drive. The following year, its trucks were involved in half the number of accidents as before the changes were implemented²¹. A survey of other trucking companies found that the highest-paid drivers were the least likely to have had an accident. Therefore, trucking companies wishing to reduce their accident rate can do so simply by raising their drivers' pay and limiting the overall number of hours they drive."