Waddell Stats Exam 2

To construct an interval estimate for the difference between the means of two populations when the standard deviations of the two populations are unknown and it can be assumed the two populations have equal variances, we must use a t distribution with how many degrees of freedom?

(n1 + n2 - 2)

The test statistic for goodness of fit has a chi-square distribution with k - 1 degrees of freedom provided that the expected frequencies for all categories are

5 or more

Chi Square is a statistic that tests?

Whether the observed frequencies match those in null hypothesis

The required condition for using an ANOVA procedure on data from several populations is that the

a. sampled populations have equal variances.

variance of the distribution of mean differences youre analyzing is

affected by the variance of both distributions

The test for goodness of fit and test of independence are designed for use with

categorical data

Data that are measured on a nominal or ordinal scale are

categorical in nature.

In the ANOVA, treatments refer to

different levels of a factor

An experimental design that permits simultaneous statistical conclusions about two or more factors is a

factorial design

We are not asking a question about a mean or standard deviation; rather, we are asking questions about a

frequency

A statistical test conducted to determine whether to reject or not reject a hypothesized probability distribution for a population is known as a

goodness of fit test.

The crucial result of a study comparing two independent groups

is the distribution of differences between the means

One of the benefits of a repeated-measures design is

it is more powerful

Generally, the ________ sample procedure for inferences about two population means provides better precision than the _______ sample approach.

matched, independent

chi-square tests focuses on what variable data

nominal

The process of allocating the total sum of squares and degrees of freedom to the various components is called

partitioning

In the analysis of variance procedure (ANOVA), "factor" refers to

the independent variable.

The ANOVA procedure is a statistical approach for determining whether or not the means of

three or more populations are equal.

Check My Work (9 remaining) In a factorial experiment, if there are x levels of factor A and y levels of factor B, there is a total of

xy treatment combinations.

distribution of mean differences will be centered around

zero