A researcher wishes to test the effectiveness of a flu vaccination.Fifty randomly selected people are vaccinated,80 randomly selected people are vaccinated with a placebo,and 300 randomly selected people are not vaccinated.The number in each group who later caught the flu was recorded.The results are shown below.
A)Yes
B)No,because the data are quantitative.
C)No,because the data do not appear to be random.
D)No,because the expected cell frequency condition is violated.
E)No,because the observed counts are too close to the expected counts.

Question

A researcher wishes to test the effectiveness of a flu vaccination.Fifty randomly selected people are vaccinated,80 randomly selected people are vaccinated with a placebo,and 300 randomly selected people are not vaccinated.The number in each group who later caught the flu was recorded.The results are shown below. 
A)Yes 
B)No,because the data are quantitative. 
C)No,because the data do not appear to be random. 
D)No,because the expected cell frequency condition is violated. 
E)No,because the observed counts are too close to the expected counts.

Quizplus · Accepted Answer

The expected cell frequency condition is violated, as the expected frequency for some cells is less than 5. This violates the assumption of the chi-square test, which requires all expected frequencies to be at least 5. Therefore, the chi-square test cannot be used to analyze this data.

A Researcher Wishes to Test the Effectiveness of a Flu