UCF QMB 3200 MAKEUP (MOD 2-5) EXAM QUESTIONS AND ANSWERS 2024

stratified random sampling A form of probability sampling; a random sampling technique in which the researcher identifies particular demographic categories of interest and then randomly selects individuals within each category. Parameter A numerical characteristic of a population, such as a population mean μ, a population standard deviation σ, a population proportion p, and so on. Target Population The population for which statistical inferences such as point estimates are made. It is important for the target population to correspond as closely as possible to the sampled population. Sampled Population The population from which the sample is taken. Sampling distribution A probability distribution consisting of all possible values of a sample statistic. sampled statistic A sample characteristic, such as a sample mean x¯, a sample standard deviation s, a sample proportion p¯, and so on. finite population correction factor Definition: The term (N-n)/(N-1) that is used in the formulas for σx¯ and σp¯ whenever a finite population, rather than an infinite population, is being sampled. The generally accepted rule of thumb is to ignore the finite population correction factor whenever n/N≤.05. simple random sampling A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size n has the same probability of being selected. standard error The standard deviation of a point estimator. point estimator The sample statistic, such as x¯, s, or p¯, that provides the point estimate of the population parameter. Central Limit Theorem A theorem that enables one to use the normal probability distribution to approximate the sampling distribution of x¯ whenever the sample size is large. point estimate unbiased A property of a point estimator that is present when the expected value of the point estimator is equal to the population parameter it estimates. confidence interval Another name for an interval estimate. margin of error The ± value added to and subtracted from a point estimate in order to develop an interval estimate of a population parameter. Confidence coefficient The confidence level expressed as a decimal value. For example, .95 is the confidence coefficient for a 95% confidence level. degrees of freedom A parameter of the t distribution. When the t distribution is used in the computation of an interval estimate of a population mean, the appropriate t distribution has n − 1 degrees of freedom, where n is the size of the sample. confidence level The confidence associated with an interval estimate. For example, if an interval estimation procedure provides intervals such that 95% of the intervals formed using the procedure will include the population parameter, the interval estimate is said to be constructed at the 95% confidence level. null hypothesis The hypothesis tentatively assumed true in the hypothesis testing procedure. two-tailed test A hypothesis test in which rejection of the null hypothesis occurs for values of the test statistic in either tail of its sampling distribution. alternative hypothesis The hypothesis concluded to be true if the null hypothesis is rejected p-value A probability that provides a measure of the evidence against the null hypothesis provided by the sample. Type I error The error of rejecting H0 when it is true. level of significance The probability of making a Type I error when the null hypothesis is true as an equality. Type II error Definition: The error of accepting H0 when it is false. Critical value A value that is compared with the test statistic to determine whether H0 should be rejected. one-tail test A hypothesis test in which rejection of the null hypothesis occurs for values of the test statistic in one tail of its sampling distribution. cluster sampling A probability sampling technique in which clusters of participants within the population of interest are selected at random, followed by data collection from all individuals in each cluster. Systematic Sampling A procedure in which the selected sampling units are spaced regularly throughout the population; that is, every n'th unit is selected. convenience sampling choosing individuals who are easiest to reach judgment sampling A nonprobability sampling method in which participants are selected according to an experienced individual's belief that they will meet the requirements of the study Which of the following is(are) true? I. The mean of a population depends on the particular sample chosen.II. The standard deviations of two different samples from the same population may be the same.III. Statistical inferences can be used to draw conclusions about the populations based on sample data. II and III A simple random sample of size n from an infinite population is a sample selected such that: each element is selected independently and is selected from the same population. The standard deviation of a point estimator is called the: standard error. The value of the _____ is used to estimate the value of the population parameter. sample statistic When drawing a sample from a population, the goal is for the sample to: match the targeted population.