“The standard deviation of a random sample is defined as the square root of the sample variance, which is the mean” (Sarkar & Rashid p.45, 2017). Because the variance is often tough to interpret, the standard deviation is used because it is easier to understand (Walker, 2009). The standard deviation makes it easier to understand by putting the dispersion in the same units as the distribution (Walker, 2009). To find the standard deviation, you would calculate the square root of the variance (Walker, 2009). Calculating the standard deviation can be both easy and hard (Walker, 2009). If you know what the variance is, like I said above, you simply take the square root of the variance, but if the variance is no known you must first find the variance …show more content…
The standard deviation is also used to show how the normal curve is discussed and divided in inferential analysis (Walker, 2009). “The index of dispersion is another measure of dispersion for normal and partially ordered ordinal variables” (Walker p.126, 2009). The index of dispersion is not usually used when measuring data, and there are not that many ways to measure nominal and ordinal level data, and people tend to use the variance and standard deviation which results in their findings being wrong (Walker, 2009). In the text it shows how the index of dispersion is used to measure and calculate nominal level data (Walker, 2009). The equation used to calculate the index of dispersion is put into a ratio form, with the actual number of data on the top and the maximum number of the data on the bottom (Walker, 2009) As an example, the text has a table with data about college attendance showing that two people were college graduates, eight people had some college, and five people had not attended college at all, bringing the maximum number of the data to fifteen (Walker, 2009). You would then take the data provided in this table and put it all through the formula to find the index of dispersion (Walker, …show more content…
I believe the best measure of dispersion to use would be the range because the range is best used with nominal level data, and since there is not much need for measurement between the different types of housing, I believe that this falls into the nominal category (Walker, 2009). Another reason I think the range would suit this category is because of the small amount of data provided (Walker, 2009). I am not sure that it is worth putting this small amount of data into formulas and calculating it. There are only 6 categories of information and they only live in one or the other type of housing (Walker, 2009). For the number of arrests, the standard deviation is 1.567, the variance is 2.455, and the range is 24 (Walker, 2009). I believe the best measure of dispersion for the number if times that someone has been arrested would the index of dispersion (Walker, 2009). The index of dispersion usually used with ordinal level data, and I believe that the data provided for the number of times someone has been arrested falls into the category of ordinal level data (Walker,
The 2SD Rule, to use this rule, you start by estimating what the mean or average value is and what the standard deviation is. The 2SD Rule then gives you a way to translate those statistics into numbers people will relate to.
Stephan, J. J. (2005). Census of State and Federal Correctional Facilities, 2005. Washington: The Bureau of Justice Statistics.
There are too many people incarcerated in the United States of America. The U.S. imprisons 724 people per 100,000. In absolute numbers United States has more of its citizens behind bars then do China or Russia combined. (Gallagher 2008). There are about thousand U.S. citizens that become incarcerated in the prison system in any given week.
Arrests by Race, 2006. Retrieved from http://www.infoplease.com/ipa/A0004896.html US Census Bureau. (2011). The 2012 Statistical Abstract. Retrieved from http://www.census.gov/compendia/statab/cats/law_enforcement_courts_prisons.html
One in every 108 adults were placed behind bars in 2012 (Dimon). That made for 2.2 million prisoners in the United States ("The Sentencing Project News - Incarceration"). This is almost the population of Houston, Texas ("Facts and Figures"). In the years following its creation, the correctional system has become a rougher place to live with nearly one percent of the whole United States population behind bars. Both the mental illness and murder rates have increased, along with return rate of prisoners. The increase of problems can be blamed on the many factors including the unstable prison environment, the rapid spread of disease and the high return rate. In general, U.S. prisoners are far worse off than those in other countries in terms
Uggen, Christopher, Sarah Shannon, and Jeff Manza. "State-Level Estimates of Felon Disenfranchisement in the United States, 2010." The Sentencing Project News -. The Sentencing Project, 20 Aug. 2012. Web. 28 Feb. 2014.
National Institutes of Health. (n.d.). NIMH Statistics Inmate Mental Health. Retrieved June 7, 2014, from National Institute of Mental Health: http://www.nimh.nih.gov/statistics/1DOJ.shtml
Variance (2) Standard Deviation () Reaction 1 7.6 x 10-4. 2.76 x 10-2.
According to the Bureau of Justice Statistics, in the year 1980 we had approximately 501,900 persons incarcerated across the United States. By the year 2000, that figure has jumped to over 2,014,000 prisoners. The current level of incarceration represents the continuation of a 25-year escalation of the nation's prison and jail population beginning in 1973. Currently the U.S. rate of 672 per 100,000 is second only to Russia, and represents a level of incarceration that is 6-10 times that of most industrialized nations. The rise in prison population in recent years is particularly remarkable given that crime rates have been falling nationally since 1992. With less crime, one might assume that fewer people would be sentenced to prison. This trend has been overridden by the increasing impact of lengthy mandatory sentencing policies.
The data gathered in the Teplin, Abram & McClelland (1994) research was conducted in the Cook county jail in Chicago during a six year period, using interview techniques during the intake process of 728 inmates. They then tracked the participants over the six years by monitoring their rap sheets. What sets this research apart from the others is that they utilized the population of a jail versus a prison. Typically, once in prison, the time spent there is long whereas in jail, the incarceration time is usually much shorter as the inmates are in jail for lesser crimes or are awaiting trial. In any case, there is a larger turnaround and more opportunity to obtain diverse long term data.
Standard Deviation is a measure about how spreads the numbers are. It describes the dispersion of a data set from its mean. If the dispersion of the data set is higher from the mean value, then the deviation is also higher. It is expressed as the Greek letter Sigma (σ).
Social Disorganization theory talks about how one’s surroundings impacts the risk of crime around them. The Social Disorganization Theory was developed to show how much a neighbors and its surroundings affect people and crime. There are many factors that go with crime according to the Social Disorganization Theory. One major factor is Ethnic Diversity. According to the Social Disorganization Theory, the more diverse urban areas are, the more likely their is to be crime committed. (Social Disorganization, 2003). The ethnicity of the community affects crime because of the lack of communication. If you have language barriers, and people who do not understand each other, they may be some tension resulting in more crime. Social Disorganization
Both answers are also to the correct first five decimal places. What this method is doing is finding a closer approximation to the square root each time we average the numbers and divide. To represent this algebraically, it would be n=a2+e. The variable n represents the square root of the number we are looking for. The variable a is the guess estimate that was made.
The extent to which a distribution of values deviates from symmetry around the mean is the skewness. A value of zero means the distribution is symmetric, while a positive skewness indicates a greater number of smaller values, and a negative value indicates a greater number of larger values (Grad pad, 2013). Values for acceptability for psychometric purposes (+/-1 to +/-2) are the same as with kurtosis.
According to BJS, “About two-thirds (67.8%) of released prisoners were arrested for a new crime within 3 years, and three quarters (76.6%) were arrested