Inferential statistics are used to determine the likelihood that a conclusion, based on the analysis of the data from a sample, is true and represents the population studied • The two common forms of statistical inference are: 1. Estimation 2. Null hypothesis tests of significance (NHTS) •Estimation theory is a branch of statistics based on measured/empirical data that has a random component •In statistics, estimation refers to the process by which one makes inferences about a population, based on information obtained from a sample •Estimation of a population parameter is to obtain a guess or an estimate of unknown value of the parameter •The estimation of the parameters of a statistical model is one of the fundamental issue in statistics •Choosing an appropriate estimator ,that is ‘best’ in one or another respect, is an important task OBJECTIVES- Describe the characteristics of the normal distribution in statistical terms • Explain the concept of a confidence interval and how it relates to an estimated parameter A point estimate of a population parameteris a single value of a statistic An interval estimate is defined by two numbers, between which a population parameterissaid to lie. For example, the sample mean x is a point estimateof the populationmean μ For example, a < x < b is an interval estimateof the populationmean p. Similarly, the sample proportion p is a point estimate of the population proportion P. It indicates that the population mean is greaterthan a but less than b