A professor of Education is interested in the relationship between students’ vis
ID: 3313983 • Letter: A
Question
A professor of Education is interested in the relationship between students’ visits to office hours held by professors and their final grades in the course. She has obtained sample data from Hardknocks University regarding these two variables. These data are cross-tabulated below.
Visits During Office Houses
Grade
None
One or Two
Three or More
C or worse
527
540
438
B
512
526
465
A
480
509
511
She hypothesizes that the more visits made by a student to office hours, the higher the likely grade. Calculate the chi-square statistics for this table. Are the two variables related in all students? Explain your answer.
I solved this using the formula and obtained .65 as the answer. Using Excel to calculate Chi Square, I got .197061. Not sure where I went wrong or if either are correct.
Visits During Office Houses
Grade
None
One or Two
Three or More
C or worse
527
540
438
B
512
526
465
A
480
509
511
Explanation / Answer
Given table data is as below
------------------------------------------------------------------
calculation formula for E table matrix
------------------------------------------------------------------
expected frequecies calculated by applying E - table matrix formulae
------------------------------------------------------------------
calculate chisquare test statistic using given observed frequencies, calculated expected frequencies from above
------------------------------------------------------------------
set up null vs alternative as
null, Ho: no relation b/w two variables OR two variables are independent
alternative, H1: exists a relation b/w two variables OR two variables are dependent
level of significance, = 0.05
from standard normal table, chi square value at right tailed, ^2 /2 =9.488
since our test is right tailed,reject Ho when ^2 o > 9.488
we use test statistic ^2 o = (Oi-Ei)^2/Ei
from the table , ^2 o = 8.97
critical value
the value of |^2 | at los 0.05 with d.f (r-1)(c-1)= ( 3 -1 ) * ( 3 - 1 ) = 2 * 2 = 4 is 9.488
we got | ^2| =8.97 & | ^2 | =9.488
make decision
hence value of | ^2 o | < | ^2 | and here we do not reject Ho
^2 p_value =0.062
ANSWERS
---------------
null, Ho: no relation b/w two variables OR two variables are independent
alternative, H1: exists a relation b/w two variables OR two variables are dependent
test statistic: 8.97
critical value: 9.488
p-value:0.062
decision: do not reject Ho
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.