Question

1) A prescription drug company believes they may have a miracle vaccine to prevent the common cold. A random sample of 100 healthy people was taken before the height of flu/cold season, with some being randomly assigned the cold vaccine. A month later, those 100 people were checked to see if they had a cold. The results are displayed in the table below

	Vaccine	NoVaccine
Cold	30	40
No Cold	20	10

a) Create a new table and calculate the expected values for each cell under the assumption that receiving a vaccine and having a cold is independent of one another.

b) Can we perform a Chi-Square test for independence on this data? Why or why not.

c) Perform the Chi-Square test for independence to determine if the variables “receiving a vaccine” and “having a cold” are independent.

Answer 1

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