Hypothesis Testing MTH 233/Elementary Statistics Abstract In this paper, Team A will be determining and discussing how there will be an overall shortage of truck drivers in the years of 2012 and 2014. We will be using a null hypothesis and alternative hypothesis to determine which hypothesis is correct. The subject that is being testing is the issue of a possible decrease in the number of truck drivers that are present on our roads today. A hypothesis test is being conducted to test the shortage of truck drivers in the coming years.
Within the past years, the trucking industry has seen a decrease in the number of drivers on the road. This is due in part to the economy as well as the many regulations that are placed upon the industry (Beard, 2011). These regulations include the number of hours that truck driver is able to drive as well as the number of potential drivers who are unable to pass the mandated drug testing and if these potential drivers have a DUI (driving under the influence) within the past five to 10 years.
Another reason for the shortage is that many of the younger population in the job force are seeking employment in the technology business; leaving an older population who is in this field who will retire in the approaching years. With these issues at hand, we can now look at the changes and how this will affect the hypothesis that is stated below. Five Step Hypothesis Testing Process Data: Year| CPS Estimate of # of Truck Drivers| 1994| 129,000| 1995| 131,000| 1996| 136,000| 1997| 146,000| 1998| 147,000| 1999| 147,500| 2000| 152,000| 2001| 151,000| 2002| 152,500| Beard, 2011) Hypothesis 1: Stating the research question: There is an overall shortage of truck drivers as the years 2012 and 2014 approach. It is said that the average shortage is from 1. 4% to 0. 5% per year. Using a significance level of 0. 05 we are testing the claim whether the shortage of truck drivers in the year 2012 to2014 will be 539,000 or greater than 539,000 (Beard, 2011). The sample mean is 143,500 drivers a year. In the next decade there will be a decrease of 110,000 drivers of all men and women, as numerous truck drivers will be retiring (Beard, 2011).
This creates a net need of 539,000 jobs to fill because not only will drivers be leaving the industry, there will be an increased demand for truck drivers over the next few years (Beard, 2011). Hypothesis 2: Specify the null and alternative hypothesis: Hypothesis is a right-tailed test because we are testing whether HA is greater than H0. H0: The shortage of truck drivers in the years 2012-2014 will be 539,000. Ha: The shortage of truck drivers in the years 2012-2014 will be greater than 539,000. Hypothesis 3: Calculate test Statistics:
N = 9 X=143,500 U = 539,000 ? = 9069. 179. Formula: t= x – u/? squared of 9. Using “t” instead of “z” as the standard deviation is from the sample t = x-u/ standard deviation/ square root of n t = 143,500- 539,000/ 9069. 179/ square root of 9 t = - 130. 8277188 (Round to three decimal places) t = - 130. 828 Hypothesis 4: Compute the probability of test Statistic or rejection region. Degrees of freedom are n-1. N= 9. 9-1= 8. Degrees of freedom (df) = 8 Using Table A-3 (and alpha of 0. 05) the critical value is: 1. 860
Hypothesis 5: State the Conclusions: The test statistic (-130. 828) is less than the critical value (1. 860). Therefore, we fail to reject the null hypothesis. There is insufficient evidence to warrant the rejection of the null hypothesis. From this hypothesis test it appears likely that the shortage of truck drivers will be 539,000. Interpreting Results and Limitations According to the American Trucking Association, there is a significant shortage of truck drivers in the United States that could reach 700,000 over the next decade (Beard, 2011).
How has this shortage affected the number of drivers on the road? Is the decrease in the number of drivers significant? This is all significant to the trucking industry primarily because there is a shortage. The trucking industry is made up of an estimated 8. 9 million people. In 2006 alone, the trucking industry logged over 430 billion miles. This was a steep increase from 2005. The economy is a chief contributor to the demand of truck drivers. If companies are not selling as much product the volume of goods transported via trucks will decrease and vice versus.
Another component to this is that unemployment is on the rise which will contribute to the shortage of drivers as companies do not have the financial means to employ more drivers. Limitations to this study include that gas prices have increased considerably since 1994. Also, major economical changes have occurred in the past decade. Conclusion With the results of this testing, it has been shown that there is a significant decrease in the number of truck drivers that are on the road today and that there will be a shortage in 2012-2014.
The reasoning is due to many factors which include the increase in the regulations and mandates that the industry has incurred over the past years. We can also see that the decrease in the number of drivers is due to the number of people who are qualified to perform this job. The results of the hypothesis testing have shown that the test statistic is less than the critical value. This shows that the hypothesis testing that was done confirms that the null hypothesis cannot be rejected and that there will likely be a shortage of truck drivers.
References Beard, B. (2011, July 30). Truck-driver shortage affecting industry. The Arizona Republic. Retrieved from http://www. azcentral. com/business/articles/2011/07/30/20110730truck-driver-shortage. html#ixzz1mrdgAqLV The U. S. truck driver shortage: Analysis and forecasts. (2005). Retrieved from http://www. cdlschool. cim/pdf/AADriverShortageStudy055. pdf Trucking faces driver shortages- increased wages. (2005). Retrieved from http://www. findatruckingjob. com/trucking-info/trucking-articles/trucking-faces-driver-shortages-higher-wages-projected