Psychology 101
Uploaded by RichundaDavis on Jan 17, 2016
Richunda Davis
1-17-2016
Psychology( Module 11)
1.Statistics are often used to describe and interpret the results of intelligence testing. They often contain the three measures of central tendency.(mean, median, mode) The mean, which is used to describe an entire set of observations with a single value representing the center of the data, is used as a standard reference point. For example, five people are waitning in line for the roller coaster. The waiting time(in minutes) of the five waiting are 3, 2, 4, 1, and 2. The mean waiting time is 3+2+4+1+2/5 = 12/5 = 2.4 minutes/ The mean is 2.4 minutes. The median is a little different. The median is used to desribe an entire set of observations with a single value representing the center of the data. The median is the middle number. It is determined by ranking the data and finding observation number [N+1] / 2. If there is an even number of observations, the median is the value midway between that of the observation numbers N / 2 AND [N / 2] +1. For example, the median in this set of observations is 13. For this ordered data the median is 13. That is, 50% of the values are less than or equal to 13, and 50% of the values are greater than or equal to 13. (Ordered data- 7 9 10 12 13 14 17 18 19.) The mode is the value that occurs most frequently in a set of observations. Mode may be used with mean and median to give an overall characterization of your data distribution. While the mean and the median require a calculation, the mode is found simply by counting the numder of times each value occurs in a data set. Usually it's easier to understand the distribution after the mode is identified. There are also cases when there is more than one mode. This simply indicates that you've actually sampled from a mixed population.
The three central tendencys can be used to describe skewed distributions, which are always shown on graphs. A distribution is said to be skewed when the data points cluster more toward one side of the scale than the other, creating a curve that isn't symmetrical. In other words, the right and the left side of the distribution are shaped differently from each other. There are normallly two types of skewed distribution, positive and negative distribution.
A distribution is postively...