https://training-course-material.com/index.php?action=history&feed=atom&title=Introduction_to_Estimation 2026-06-23T05:56:05Z Revision history for this page on the wiki MediaWiki 1.45.3 https://training-course-material.com/index.php?title=Introduction_to_Estimation&diff=24052&oldid=prev 2014-11-25T17:25:59Z

<p></p> <p><b>New page</b></p><div>{{Cat|Estimation|1}}<br /> <br /> == Learning Objectives ==<br /> # Define statistic<br /> # Define parameter<br /> # Define point estimate<br /> # Define interval estimate<br /> # Define margin of error<br /> <br /> <br /> == Introduction to Estimation ==<br /> One of the major applications of statistics is estimating population parameters from sample statistics . For example, a poll may seek to estimate the proportion of adult residents of a city that support a proposition to build a new sports stadium. Out of a random sample of 200 people, 106 say they support the proposition. Thus in the sample, 0.53 of the people supported the proposition. This value of 0.53 is called a point estimate of the population proportion. It is called a point estimate because the estimate consists of a single value or point.<br /> <br /> Point estimates are usually supplemented by interval estimates called confidence intervals . Confidence intervals are intervals constructed using a method that contains the population parameter a specified proportion of the time. For example, if the pollster used a method that contains the parameter 95% of the time it is used, he or she would arrive at the following 95% confidence interval: 0.46 &lt; π &lt; 0.60. The pollster would then conclude that somewhere between 0.46 and 0.60 of the population supports the proposal. The media usually reports this type of result by saying that 53% favor the proposition with a margin of error of 7%.<br /> <br /> In an experiment on memory for chess positions, the mean recall for tournament players was 63.8 and the mean for non-players was 33.1. Therefore a point estimate of the difference between population means is 30.7. The 95% confidence interval on the difference between means extends from 19.05 to 42.35. You will see how to compute this kind of interval in another section.<br /> <br /> == Questions ==<br /> <br /> &lt;quiz display=simple &gt;<br /> {You estimate population ___________ from sample ___________. <br /> <br /> |type=&quot;()&quot;}<br /> + parameters; statistics<br /> - statistics; parameters<br /> <br /> {<br /> {{Show Answer|<br /> A parameter is a value calculated in a population. A statistic is a value computed in a sample to estimate a parameter.<br /> }}<br /> }<br /> <br /> <br /> {Select all that apply. Of the people sampled in a state, 0.63 support Senator A. This value of 0.63 is: <br /> <br /> |type=&quot;[]&quot;}<br /> - parameter<br /> + statistic<br /> + point estimate<br /> - interval estimate<br /> - confidence interval<br /> <br /> {<br /> {{Show Answer|<br /> The proportion of 0.63 is a statistic and point estimate because it is the proportion obtained from the sample and an estimate of the population proportion.<br /> }}<br /> }<br /> &lt;/quiz&gt;</div>

Cesar Chew