QMB UCF FINAL STUDY GUIDE1 QUESTIONS AND ANSWERS 2024

Suppose a political party wants to estimate how favorable a certain candidate is to state voters. To do so, a sample of 400 registered voters were selected. Suppose 160 found the candidate "favorable". An estimate of the proportion of the population of registered voters is 160/400=40%. This is an example of what? Example of finite sample Suppose a new tire is being developed and the manufacturer wants to know the useful life of the new type of tire. A sample of 120 tires were tested and the test results show a sample mean = 36500 miles. An estimate of the population mean of the new type of tire is 36500. This is an example of what? Example of infinite sample What if the population is too large or we don't have all the data of the population? The solution is to take a sample of the population to estimate the population parameters. Sampling from a finite population: choosing a simple random sample of size n from a finite population of size N where each possible sample of size n has the same probability of being selected. choosing a simple random sample of size n from a finite population of size N where each possible sample of size n has the same probability of being selected. 1. Assign a random number to each element of the population. 2. Select the n elements corresponding to the n smallest random numbers. Excel form for Random Finite Sample =Rand() Sampling from an infinite population: A random sample of size n form an infinite population is a sample selected meeting the following: 1. Each element comes from the same population; 2. Each element is selected independently. The point estimator is the sample size for the population parameter. True or False True parameters a numerical characteristic of a population such as population mean, population standard deviation, and population proportion. simple random sample size n from a finite population of size N is a sample selected such that each possible sample of size n has the same probity of being selected. Based on the use of randome numbers Infinite population when the population is too larger or the elements of the population are generated by an ongoing process so there is no limit to the number of elements that can be generated, we can not select a simple random because we cannot construct a frame consisting of all the elements statistics recommends selecting what is called a random sample. Random Sample size n from an infinite population is a sample selected such that the following condition is satisfied. 1. Each element selected comes from the same population 2. Each element is selected independently Big data any set of data that is too large or too complex to be handled by standard data processing techniques and typical desktop software Central limit theorem a theory that allows one to use the normal probability distribution to approximate the sampling distribution of x-bar whenever the sample size is large Cluster sampling a sampling method where the population is first divided into clusters and then a simple random sample of the cluster is taken. Finite refers to the population that can be counted for easily, they are not unlimited in size. Ex- books in a library convince sampling a nonprobability method of sampling whereby elements are selected for the sample on the basis of convenience. Coverage error Non-sampling error that results when the research objectives and the population from which the sample is to be drawn from are not aligned Frame a listing of the elements the sample will be selected from Nonproblity not all population members have an equal chance of participating in the study Judgment sampling a nonprobability method of sampling whereby elements are selected for the sample based on the judgment of the person doing the study Measurement error Nonsampling error that results from the incorrect or imprecise measurement of the population characteristics of interests nonresponsive error when one segment participants are less likely to respond to the survey mechanism than potential respondents that belong to other segments of the population Nonsampling error All types of errors other then sampling error, such as coverage error, nonresponse error, measurement error, interviewer error, and processing error point estimate the sample sats, x-bar, and p-bar that provides the point estimate of the population parameter Sample Satistics the value of the sample sats is used to estimate the value of the corresponding population parameter sampling distribution a probability distribution consisting of all possible values of a sample statistic sampling error an error that occurs because a sample, and not the entire population, is used to estimate a population parameter standard error the standard deviation of a point estimator stratified random sampling a probability sampling method in which the population is first divided into strata and a simple random sample is then taken from each stratum systematic sampling a method for selecting a sample from a population in a randomized manner, as to minimize sampling error tall data data set that has so many observations that traditional statistical inference has little meaning target population the population for which statistical inferences such as point estimates are made. very important for target population to correspond as closely as possible to the sampled population unbiased point estimator= population parameter variety the speed at which the data are generated volume the amount of data generated wide data a data set that has so many variables that simultaneous considerations of all variables are infusible We can look a sample in what two ways? finite and infinite Suppose a political party wants to estimate how favorable a certain candidate is to state voters to do so, a sample of 400 registered voters were selected. suppose 150 found the candidate "favorable". An estimate of the proportion of the population of registered voters is 160/40=40%. This is an example of a? finite sample A new tire is being developed and the manufacture wants to know the useful life of the new type of tire. a sample of 120 tires were tested and the results show a sample mean of 36500. An estimate of the population mean of the new type of tire is 36500. This is an example of a? Infinite sample