Imagine that a professor made a quiz with 20 multiple choice questions. For each
ID: 3318482 • Letter: I
Question
Imagine that a professor made a quiz with 20 multiple choice questions. For each question, students must select only one answer from four options (“A”,” B”, “C”, and “D”). For 4 of the questions the correct answer was “A”, for 6 of the questions the correct answer was “B”, for 7 of the questions the correct answer was “C” and for 3 of the questions the correct answer was “D”. The professor was concerned that he may be biased about which letter he assigns the correct answer to so he decided to use Chi square to test if the four options had an equal chance of being the correct answer.
a. How many degrees of freedom will this test have?
b.What is the obtained Chi square value for this test?
c. What is the probability value for this test? (Give your answer to at least 3 places past the decimal point.)
Explanation / Answer
The statistical software output for this problem is:
Chi-Square goodness-of-fit results:
Observed: Oi
Expected: All cells in equal proportion
Hence,
a) Degrees of freedom = 3
b) Obtained Chi square value = 2
c) Probability value = 0.572
N DF Chi-Square P-value 20 3 2 0.5724