The graph shows the ratio of pencils to pens sold at the school bookstore.
Pencil and
Pen Sales
y
Number of Pens
20
18
16
14
12
10
8
6
4
2
X
0
2 4 6 8 10 12 14 16 18 20
Number of Pencils
If the bookstore sells 12 pencils, what is
the ratio of pencils to pens sold written as
a fraction?


Agroup of student volunteers participates in a study designed to assess several behavioral interventions for improving output in a repetitive task. prior to the beginning of the study, all volunteers unknowingly observed, and their output is measured. at the beginning of the study, prior to any intervention, the volunteers perform the same task under the observation of a study administrator, and their overall output increases. which of the following terms describes this phenomenon? a. simpson's paradox b. hawthorne effect are d. novelty effect d. pygmalion effect e. observer-expectancy effect