# STATS SHET

version from 2017-03-08 09:17

## Section 1

continuous random variable has an infinite number of possible values that can be represented by an interval on the number line.
continuous probability distribution or probability density function.The probability distribution of a continuous random variable is called
normal distribution.The most important probability distribution in statistics is the
normal curveThe graph of a normal distribution is called the
(1) Mean, median mode are equal, (2) Bell shaped, (3) Total are is equal to 1, (4) normal curve approaches, but never touches5 Properties of a Normal Distribution
inflection pointsThe points at which the curve changes from curving upward to curving downward are called
normal distribution can have any mean and any positive standard deviation.
standard normal distribution is a normal distribution with a mean of 0 and a standard deviation of 1.
(1) The cumulative area is close to 0 for z-scores close to z = 3.49, (2) The cumulative area increases as the z-scores increase, (3) The cumulative area for z = 0 is 0.5000, (4) The cumulative area is close to 1 for z-scores close to z = 3.494 Properties of the Standard Normal Distribution
sampling distribution is the probability distribution of a sample statistic that is formed when samples of size n are repeatedly taken from a population.
sampling distribution of sample means.If the sample statistic is the sample mean, then the distribution is the

## Section 2

ParameterA descriptive measure of the population
StatisticA descriptive measure of a sample
Point EstimateA single value estimate for a population parameter
Point EstimateMost unbiased point estimate of the population mean μ is the sample mean
Interval EstimateAn interval, or range of values, used to estimate a population parameter.
Level of confidence The probability that the interval estimate contains the population parameter.
Sampling errorThe difference between the point estimate and the actual population parameter value.
Margin of ErrorThe greatest possible distance between the point estimate and the value of the parameter it is estimating for a given level of confidence, c.
maximum error of estimate or error tolerance.Sometimes, Margin of Error is called