Q3 blog post number 3

In this blog i will be summarizing/analyzing pages 105-145 of Leonard Mlodinow's the drunkard's walk. It starts off where we left off, Pascal's death. We carry on with Thomas Bayes, a mathemetician and minister who lived during the 18th century. Bayes' greatest contribution to probability are his theories on conditional probability. That is what are the chances of something happenning if something else happens. The easiest example is this, what is the probablity that a family has 2 girls if they have 2 kids and one is girl? 1/3, because there are three combinations whith 2 kids and one girl (the sample size) and only one has 2 girls. another one of Bayes great laws is the law of large numbers or the golden theorem, " This law is the simplest law that was ever developed in probability" (121). As the book states it is pretty easy to understand, the larger the number of trials conducted the closer to the real mean you will get, and the more accurate you test will be. An example is this, if you flip a coin 10 times how many will be heads? how about if you flip it 1 million time? the second time the mean will be much closer to half of the number of trials. This effects everyday life and by simply applying this to other scenarios we can see that it really can help us out.
In the next chapter Mlodinow goes on to tell us the when he wrote a paper for his son's english class (who is in 10th grade and Mlodinow was editing but got carried away) only got a 93 he was infuriated. He then later learned that one of his colleaues (has a Phd in english and writes for the new york times) did the same thing but only got an 80%. Then two students turned in the same paper and one scored a 90% while the other only got a 79%(Mlodinow 136). How can this happen? We see that with thourough analyzation that when teachers grade numerous papers each day they get more tired and grade harder as they go on, or the grade later and get sloppier. So in fact your grades are all part of probability. But because of Bayes' golden theorem this is not true, as the more papers you write and get graded the closer to the true value of your work you will get. So grades have an amount of variance (atleast english grades) and this can change the scales roughly 10 % in either direction. He caries on to tell us that all measurements including human calculation contain error and there is alw to counter this error.