Bell curve?
Charles Murray's book on the Bell curve suggest that there is an intelligence factor g that is inherited and can be measured by standard IQ test and that g is predictive of success in all of life's endeavors. criticisms: 1) That there are different talents needed for different activities and not a single factor g 2) The evidence for heritability is actually very weak because the studies were done in situations where the environments were similar. When people looked at large variations in environments the degree of heritability is actually quit small. 3) New research on what an IQ test actually measures indicate there is a large cultural component. Average test scores have increased several points a decade over the last fifty years with almost all the increase due to the subtest that people thought was culture neutral.
How do I create a bell curve?
So in one of my classes we designed an experiment to test the affect of music on heart rate, blood pressure and rate of respiration. I have m the data and I have run my student's t-test (paired and two tailed) but I have no idea how to create the bell curve in excel. I have seen directions for one set of data in excel. I have two per type of measurement and genre of music. So for example I have a resting heart rate and heart rate after listening to classical music. (Repeat for metal and pop) I also have blood pressure before and after listening to classical. (Repeat for metal and pop). Finally I have rate of respiration before and after classical. (Repeat for metal and pop) I want all the heart rates on a bell curve, all the blood pressures on a separate bell curve and finally I want all the rates of respiration on their own bell curve. I am not sure how to do this and now that I have left class I am confused as to whether or not the resting heart rates go on the bell curve or not? Our hypothesis is different genres of music affect heart rate, blood pressure and rate of respiration. (We of course have specific predictions as to how) The null hypothesis is that different genres of music do not etc. I think I need a break down of normal distributions and bell curves and then directions on how to create that on excel given my data. I can give more specific infor on our data, feel free to ask if you need something clarified.
IQ bell curve?
It is because most of the yahoo users who post their IQ's have taken it from an online test, which can inflate their scores. However, even with professional ratio IQ tests being replaced with deviated tests many are finding that most participants in IQ tests are scoring high. That is because the IQ is usually only administered if someone believes a) the person has a learning disability or b) They are bright. Most with an average IQ will not spend the money or time on taking the test, which skews the results. IQ tests were not created to test "genius" or the "gifted" but to weed out the handicapped. Our society has wrongly began to use IQ tests as a form of testing genius, and the involves a certain level of knowledge, but the IQ test was only ever suppose to tests a person capability to process information. High IQ individuals have a higher standard deviation since the test was not designed to test +40 deviations. Therefore, anyone scoring about 130 one day may score 150 the next and 120 on another. The smartest woman in the world, whose average intelligence is 190, has scored between 168 to 210 on the test. Therefore, the definition of "genius" you find in IQ tests as being 140 and above is really quite hard to verify because a persons ability to take an exam varies from day to day.
Yes.The area under the curve is a probability.The x-axis is measured in the units of the thing that has the Normal distribution.So the y-axis has to be measured in units of probability divided by units of the thing with the distribution.For example, suppose the graph is the distribution of height of adult males in centimeters. Then the y-axis units are probability / centimeters. Then when you multiply a y-axis value times an x-axis value to get an area, the units are probability.That unit doesn’t make a lot of sense at first, but that’s because the value of a probability density function—f(X)—doesn’t make a lot of sense at first. Normally we define the probability density function as the derivative of the cumulative distribution function—F(X). The cumulative distribution function is measured in units of probability, so it’s easy to describe, F(X) is the probability of a random observation being less than or equal to X.Say the value of f(X) is 0.01 at 175. What does that mean? It means that for a small range in centimeters around 175, say from 174.9 to 175.1, the probability of a random adult male being found in the range is about 0.01 times the width of the range in centimeters, so 0.01*(175.1 - 174.9) = 0.002, so we thing about 0.2% of adult men will have a height in that range. If we measured in inches instead of centimeters, the value of f(X) would be 0.0254 instead of 0.01, because the new height units are 2.54 larger than the old height units, so the measured values are divided by 2.54, so f(X) which is measured in inverse unit will be 2.54 as large.
Bell curve question?!?
This is missing way too much information. If you are standardizing a test using a bell curve then you must either know all the other grades or at least the standard deviation of that curve. if 70 marks = 4.0 and most students got between 65 and 75 marks then 60 would be very poor. perhaps only 10% if most students got between 45 and 80 then 60 would be reasonably good. Slightly above average. Perhaps 3.3 Grade points or 55 %
What is a reverse bell curve?
For the best answers, search on this site https://shorturl.im/avv5c If you think that lesser intelligent people are having more kids while intelligent people are having fewer kids, you're not just imagining that. It's actually been verified by scientific studies. However, the good news is that's not declining as quickly as we may have expected. It turns out that IQ is only declining .9 IQ points per generation. IQ is measured on a scale where 100 is currently considered average, so over the course of ten generations you'd only lose 9% of the intelligence. Ten generations is a very long time. Although the average is declining, the random combination of different genes from different parents means that IQ is distributed on a bell curve. Currently, 2.2% of the population has an IQ of 128 and over... if you look at even higher IQ scores such as 150 or 170 there are still quite a few people in these ranges. Not all that high of a percentage, but they are out there. So even after 10 generations, and a drop of 9 IQ points, there would still be some people in the upper percentiles, just not as many of them. Society doesn't really need a lot of engineers, business leaders, and so forth to function... the majority of the work done in the US doesn't require an extremely high IQ score, and as long as there are some people in the upper IQ ranges to make everything else work, capitalism will find those people and find a way to move them into the positions that make the whole system work. So considering that the average is only dropping about 1% per generation, and intelligence is not evenly distributed, then society will be okay for at least a few more centuries to go, at the rate we're going. It's not a problem that would have to be dealt with right away, but it still raises the question of how to make the next generation a bit smarter and better off without violating anyone's civil rights. Personally I would think it would be a good idea to rewrite the tax laws so that tax credits for kids are based in part on a percentage of total income, not just a flat dollar amount. In other words, people in the $100K+ tax bracket should get a large tax discount for having 3 or 4 kids, and the more kids they have the lower their taxes should be. Any highly intelligent person having four well educated, intelligent, well behaved kids is paying their dues to society in this way, and should be given discounts off their taxes accordingly.
In probability theory, the normal (or Gaussian or Gauss or Laplace–Gauss) distribution is a very common continuous probability distribution. Normal distributions are important in statistics and are often used in the natural and social sciencesto represent real-valued random variables whose distributions are not known.[1][2]A random variable with a Gaussian distribution is said to be normally distributed and is called a normal deviate.It looks like a bell!Normal distribution - Wikipedia
What is a Bell-shaped curve? Why does data form a bell shaped curve?
----------------------------------------... bell curve A symmetrical bell-shaped curve that represents the distribution of values, frequencies, or probabilities of a set of data. It slopes downward from a point in the middle corresponding to the mean value, or the maximum probability. Data that reflect the aggregate outcome of large numbers of unrelated events tend to result in bell curve distributions. The Gaussian or normal distribution is a mathematically well-defined bell curve used in statistics and in science generally. bell curve graph showing the distribution of a set of test scores where the average grade is a C . bell curve graph showing the distribution of a set of test scores where the average grade is a C
Most of it, especially the warning about the consequences of what would happen if people ignored their concerns.Steve Sailer (someone who makes Murray look mainstream, but is nonetheless honest and insightful) writes :As the subtitle Intelligence and Class Structure in American Life explains, The Bell Curve is chiefly a book about the growth of inequality. In 1994 they saw three main tendencies:An increasingly isolated cognitive elite.A merging of the cognitive elite with the affluent.A deteriorating quality of life for people at the bottom end of the cognitive ability distribution.They warned:Unchecked, these trends will lead the U.S. toward something resembling a caste society, with the underclass mired ever more firmly at the bottom and the cognitive elite ever more firmly anchored at the top, restructuring the rules of society so that it becomes harder and harder for them to lose.That seems awfully timely.They asked:Do you think the rich in America already have too much power? Or do you think the intellectuals already have too much power? We are suggesting that a “yes” to both questions is probably right. And if you think the power of these groups is too great now, just watch what happens as their outlooks and interests converge.By contrast:All of the problems that these children [of low intelligence] experience will become worse rather than better as they grow older, for the labor market they will confront a few decades down the road is going to be much harder for them to cope with than the labor market is now.A New Caste Society