Introduction to Measures of Dispersion for Numerical Data When describing a distribution, it is important to have some measure of where the middle is. With a little thought, we can see that, if we have a measure of the middle, we still need more information to ...
Introduction to Histograms and Boxplots Numerical data may be discrete or continuous. In this lesson, we will discuss presenting information on the distributions of discrete and continuous random variables in tabular form. Then we will learn how to display ...
Introduction to Describing and Displaying Bivariate Data Often, two or more numerical measurements are taken on each observational unit. For example, the weight and length of each fish taken from a lake may be recorded. In studies of wetlands, the phosphorus ...
Introduction to Basic Ideas in Probability For most studies, we want to use the study to make decisions or to draw inferences about the research question. Before we are prepared to do this, we need to establish some understanding of probability, discrete and ...
Introduction to Discrete Probability Distributions Because some probability distributions occur frequently in practice, they have been given specific names. In this lesson, we will discuss three discrete probability distributions: the Bernoulli, the binomial, and ...
Introduction to Continuous Probability Distributions As was the case with discrete distributions, some continuous random variables are of particular interest. In this lesson, we will discuss two of these: the uniform distribution and the normal distribution. ...
Introduction to Sampling Distributions and the t-Distribution Study Guide The distribution of a random sample from a population is called the sample distribution. Using sample values, we can obtain estimates of the population parameters, such ...
Introduction The Law of Large Numbers and the Central Limit Theorem If a random sample of size n is taken from a population having a normal distribution with a mean μ and a standard deviation σ, then the sampling distribution of the sample mean
Introduction to Sample Surveys The results of surveys are presented almost daily in newspapers, over the radio, and on television. From surveys, the proportion p of the population with a certain trait or opinion can be estimated. In fact, if the sample size is ...
Introduction to Confidence Intervals for Proportions Studies are conducted and samples are drawn to learn more about one or more populations. If the form and parameters of the population distribution are known, there would be no need to sample. Sampling gives ...