Biology
Psychology
Education

# Explain concept and the use of central tedency?

###### 10/24/2007

1

1

1 8 9

1 8 9 10

1 4 5 8 9 10 11

1 2 3 4 5 8 9 10 11 12

This distribution of numbers is said to be skewed since it looks like a declining slope, rather than a more or less evenly distributed set that would look more like a "hill." An inclining slope would also be considered a skewed distribution. Looking a these numbers, you could safely if you don't score "1" on the test, you will probably score somewhere between 8 and 10, and are very likely to score between 4 and 11. This distribution could represent, just as an example, a test where you get one point for writing your name, and then you either know most of the answers, or you know almost none of them, and get a coupld right by guessing. That is assuming there were only 12 possible points on the test, which may not be the case. It could very well be a distribution of scores on a 20 item test, which would then say something else about the test. Lets say that the test involves 20 possible points, one point per question, and that we were expecting that scores would be "normally distributed." That means we were expecting a mean of 10, an average of 10, and a mode of 10, with 86% of the scores falling within one standard deviation of the mean (that is another discussion), but basically "in the middle of" the distribution with 8 % on each end of the curve where the highest and lowest scores are represented, creating a curve that looks like a hill. If, despite, our expectation, we got scores as listed above, it would tell us that our assumption may not be true for the sample population we are studying, and that there are some factors impacting the way people score on the test that we need to look at more closely.