Information: Thirty psychology students are asked which psychology class they li
ID: 3300011 • Letter: I
Question
Information: Thirty psychology students are asked which psychology class they like best. The choices are research methods, social psychology, and developmental psychology. It turns out that 25 prefer research methods, 3 prefer social psychology and 2 prefer developmental psychology.
A. Perform (showing your work) the appropriate statistical analysis on this data set. (Chi Square) (15 pts) (do not worry if your symbols are off as that is not important).
B. Write out the APA statistical result and the real world conclusion. (10 pts)
Explanation / Answer
Given table data is as below
25 prefer research methods, 3 prefer social psychology and 2 prefer developmental psychology
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calculation formula for E table matrix
E = we left with three choice out of 30 = 30/3 = 10
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expected frequecies calculated by applying E - table matrix formulae = 10
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calculate chisquare test statistic using given observed frequencies, calculated expected frequencies from above
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set up null vs alternative as
null, Ho: the choices of students are independent
alternative, H1: exists a relation b/w choices made by students
level of significance, = 0.05
from standard normal table, chi square value at right tailed, ^2 /2 = 5.99
since our test is right tailed,reject Ho when ^2 o > 5.99
we use test statistic ^2 o = (Oi-Ei)^2/Ei
from the table , ^2 o = 33.8
critical value
the value of |^2 | at los 0.05 with d.f n-1 = 3 - 1 = 2 is 5.99
we got | ^2| = 33.8 & | ^2 | =5.99
make decision
hence value of | ^2 o | > | ^2 | and here we reject Ho
ANSWERS
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null, Ho: the choices of students are independent
alternative, H1: exists a relation b/w choices made by students
test statistic: 33.8
critical value: 5.99
decision: reject Ho
we conlcude that the three methodology choices are dependent to each other
Oi Ei Oi-Ei (Oi-Ei)^2 (Oi-Ei)^2/Ei 25 10 15 225 22.5 3 10 -7 49 4.9 2 10 -8 64 6.4 33.8