Tag: math

Someone Can’t Do Math

Posted onAuthorcahwyguy

I was doing my normal perusal of the papers this morning, reading an article about Arcadia (a city in Southern California) and the problem of selling homes with the number “4” in the address to Chinese… when I run across the following:

“There are 20,000 homes in Arcadia. One in four has a number four in it. That’s a potential of 3,000 addresses that could be changed,” said Councilman Roger Chandler, who is against restarting the program [to allow people to change their house numbers].

How’s that again? If home numbers are distributed uniformly, then I would think the chance of having a four in the number should be closer to 1 in 10, although that might be skewed by the first digit. That would certainly increase the odds of the first digit being 1, and of course the odds of a zero are lower because we drop leading zeros in addresses. But for the number “four”, 1 in 4 seems far too low to me.

But let’s suppose they are correct on the odds being 1 in 4. Then if there are 20,000 addressed, wouldn’t that be a potential of 5,000 addresses, as 5,000 x 4 = 20,000.

Somehow, I think this councilman doesn’t know what he’s talking about.

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Arguing Esoterica

Posted onAuthorcahwyguy

Back in high school, I had an ongoing argument with one of my best friends about a mathematical problem: Whether .9999….. is equal to 1. I argued that it was; he argued that it wasn’t. So, I was please to see an entry in Slashdot today regarding the controversy, including at 28-page paper.

Over the years, I’ve lost touch with this friend. Last I knew, Mark was a VP at Racal Vadic, but I haven’t heard from him in years (I’d guess at least 10). He’s one of the high school folks I’d love to get back in touch with.

I’ll note this is one of those great questions that I think shows something about your inner thinkings. Other “great questions” include the superhero question and the wealth question. So let’s see where you stand:

ETA: Because you can’t edit polls: “servents” -> “servants”. For a reference and details on the Superhero question, take a listen to this segment of “This American Life”. For the Wealth question, take a listen to this Planet Money episode. Lastly, .99999….. refers to an infinite number of 9s, also called “point nine repeating”.

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Wednesday News Chum: Children and Education, Barbie and Teen Driving

Posted onAuthorcahwyguy

Ah, Wednesday lunch. Time for some chum to chew upon. I’m not sure if there’s a theme in these items yet — perhaps you can find it.

  • From the “Government Intrusion” Department: The New York Times has an interesting article on the National Children’s Study. This is a multi-billion dollar study authorized by Congress whereby the National Institutes of Heath will be following newborn children from before birth to age 21. The study’s goal is to examine how environment, genes and other factors affect children’s health, tackling questions subject to heated debate and misinformation. To do this all sorts of data will be collected. For exampel, quoting from the article, for one pregnant woman… “Researchers would collect and analyze her vaginal fluid, toenail clippings, breast milk and other things, and ask about everything from possible drug use to depression. At the birth, specimen collectors would scoop up her placenta and even her baby’s first feces for scientific posterity.” Here’s another quote, regarding the specimens collected: “Specimens include blood, urine, hair and saliva from pregnant women, babies and fathers; dust from women’s bedsheets; tap water; and particles on carpets and baseboards. They are sent to laboratories (placentas to Rochester, N.Y., for example), prepared for long-term storage, and analyzed for chemicals, metals, genes and infections.” It sounds like quite an effort, and for some, quite an intrusion. So, the real question: to what level are intrusions appropriate (with informed consent, of course) in the name of science?
  • From the “Pick a Career” Department: You know that flighty-blond Barbie. She can never seem to settle on a career, be it Astronaut or Doctor. So what is she doing this year? Voters have made her a news anchor and a computer engineer (the latter, the article notes, was designed with the help of the wonderful organization SWE). An interesting article in CurbedLA notes what careers were not chosen: in particular, they declined to allow her to pursue a career in environmentalism, surgery, or architecture. With respect to the latter, the Mattel spokeswoman stated that Barbie’s target audience (girls aged three to eleven) could not understand the complexities of an architect’s career. (Oh, SWE, did you hear that? Perhaps we need Civil Engineer Barbie). The article also mentions a professor at University of Buffalo, who put together an “Architect Barbie” exhibition at the University of Michigan as a response, with students and faculty creating their own archiBarbies (including a pregnant Glass Ceiling Barbie).
  • From the “I Picked The Wrong Day To Become a Woman” Department: More bad news for the girls out there. According to the Chicago Tribune, Allstate Foundation’s “Shifting Teen Attitudes: The State of Teen Driving 2009” report indicates that 27% of girls admit to speeding at least 10 miles over the speed limit, vs. 19% of boys. Also, 16% of girls report that they are very aggressive while driving, up from 9% in 2005. Meanwhile, 13% of teen boys admitted to being very aggressive while driving, vs. 20% in 2005.
  • From the “School Days, School Days” Department: A trio of interesting articles related to high school…

    In Arizona, school officials in a Tucson suburb took notice of the long bus rides… and decided to do something about it. According to the NY Times, they outfitted the bus with free WiFi. Surprise, surprise. The bus has become rolling study hall. Although some students do play games, many use the time to get a jump on homework assignments, do research, and yes, socialize on Facebook.

    In Utah, the school districts are facing a significant budget shortfall. One legislator’s solution: Make 12th Grade Optional. Basically, the proposal would offer incentives to encourage students to graduate early. The thought behind this is that most seniors take their senior year off. Hmmm, perhaps in Utah.

    But eight states are going even further: they are permitting students to enter community college after 10th grade. These states (Connecticut, Kentucky, Maine, New Hampshire, New Mexico, Pennsylvania, Rhode Island and Vermont) are introducing a program allowing 10th graders who pass a battery of tests to get a diploma two years early and immediately enroll in community college. Students who pass but aspire to attend a selective college may continue with college preparatory courses in their junior and senior years. Students who fail the 10th grade tests, known as board exams, can try again at the end of their 11th and 12th grades. The tests would cover not only English and math but other subjects like science and history. The new system of high school coursework with the accompanying board examinations is modeled largely on systems in high-performing nations including Denmark, England, Finland, France and Singapore. It’s a pilot program. I’m not sure it’s a good idea, but then I’m a traditionalist.

Hmmm, I guess this post did have a theme after all.

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Govt Standards Organization Proposes to Shorten the Inch

Posted onAuthorcahwyguy

Today in History…

Dr. Lyman J. Briggs, director of the United States Bureau of Standards, wants to shorten the inch. It is too long, he says, and furthermore, the difference between the length of the inch in this country and in Great Britain “is intolerable.”

In line with Dr. Briggs recommendation, the House Committee on Coinage, Weights, and Measures, has reported out a bill which would fix the length of the inch and the weight of a pound. The bill proposes to establish the inch to equal 25.4 millimeters exactly. This would shorten the inch by two parts in a million. It is now 25.40005 millimeters, as against 25.39996 in Great Britain.

Dr. Briggs, in urging the legislation, hastened to assure industry that the change would not be disturbing.

“I wish to emphasize,” he said, “the fact that the change will not disturb industry in any way. Industry, from a practical standpoint, will not realize that a change has been made, because the change is too small; it is far within the limits of tolerance permitted in making industrial measurements.”

Note that this was in February 1938. Note that this proposal must have gone through, for in the US an inch is still defined to be 25.4 millimeters (to be precise, 1/36th of a yard, which is 0.9144 meters. This definition was standardized on July 1, 1959 (so the 1938 proposal took a long time to be adopted). Given that a meter is defined as the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second, this means than an inch is, oh, you do the math!.

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