Blog

What is the value of Σ(X – 1)2 for the following scores?  Scores: 1, 2, 1, 4

A student investigated how washing with soap affects bacteria levels on the hands. She tested three different methods—washing with water only, washing with regular soap, and washing with antibacterial soap. She randomly assigned 99 students to one of the 3 treatments. Participants washed their hands with the assigned method and cultures were taken and incubated. Based on the SPSS output below, was there a significant difference among the three hand-washing methods and why?

The following table shows the results of an analysis of variance comparing three treatment conditions with a sample of n = 10 participants in each treatment.  Note that several values are missing in the table.  What is the missing value for SStotal?Source         SS       df      MS      Between     20      xx      xx      F = xxWithin          xx       xx        2Total              xx       xx       

A sample has M = 72 and s = 4.  In this sample, what is the X value corresponding to z = –2.00?

An independent-measures study comparing two treatment conditions produces a t statistic with df = 18.  If the two samples are the same size (n1 = n2), how many participants were in each of the samples?

In analysis of variance, what is a factor?

In a linear regression equation with the form y = bx + a, what does the “a” represent?

For a two-factor study with 2 levels of factor A, 2 levels of factor B, and a separate sample of 10 participants in each treatment condition, what is dfwithin treatments?

Using letter grades (A, B, C, D, and F) to classify student performance on an exam is an example of measurement on a(n) ____ scale of measurement.

For a two-factor study with 2 levels of factor A, 2 levels of factor B, and a separate sample of 10 participants in each treatment condition, the two means for level A1 are 4 and 1, and the two means for level A2 are 3 and 2.  For these data, what is the value of SSbetween treatments?