Stat 201 Chapter 6 – Flashcards

-Symmetric and bell shaped graph -mean = 0 -Standard deviation = 1 ?Area, probability,? percentages, and relative frequencies are all used interchangeably when working with normal distributions.

The graph of a uniform distribution is rectangular because the values are spread evenly over a range. That means every value in the range is equally likely.

Areas, probability, and relative frequencies can be used interchangeably when working with normal? distributions

Mean differs from 0 and SD deffers from 1

is equivalent to finding probabilities associated with distributions that are standard normal distributions because there is a correspondence between area and probability.

A? z-score is not an area under the normal curve. Distances along the horizontal axis are represented by? z-scores, while regions under the curve are represented by areas. -A? z-score is a conversion that standardizes any value from a normal distribution to a standard normal distribution. -If values are converted to standard? z-scores, then procedures for working with all normal distributions are the same as those for the standard normal distribution. -The area in any normal distribution bounded by some score x is the same as the area bounded by the equivalent? z-score in the standard normal distribution.

a data value associated with an area of 0.85 to its left

(such as a sample mean or sample? proportion) is the distribution of all values of the statistic when all possible samples of the same size n are taken from the same population.? (The sampling distribution of a statistic is typically represented as a probability distribution in the format of a? table, probability? histogram, or? formula.)

is the distribution of sample? proportions, with all samples having the same sample size n taken from the same population.

The central limit theory applies whenever n greater than>30. Because n greater than >? 30, the sampling distribution of the mean ages can be approximated by a normal distribution with mean ? and standard deviation (Standard Deviation)/Square root of n if the sample size is large? enough, the distribution of sample means can be approximated by a normal? distribution, even if the original population is not normally distributed.

-The graph of the distribution is symmetric. -The graph is centered around the mean. -The graph of the distribution is? bell-shaped.

areas, probability, and relative frequencies