Question

7. Consider the following results of a study entitled “Caffeine as a Protective Factor in Dementia and Alzheimer’s Disease.”. The study followed 1,409 adults for 21 years. During that time, 61 adults developed dementia. The researchers classified the research participants into three categories, based on coffee consumption levels: Low (0 to 2 cups per day), Medium (3 to 5 cups per day) and High (6 or more cups per day).

• Are developing dementia and low coffee consumption independent of each other?

  	Low Coffee Consumption	Medium Coffee Consumption	High Coffee Consumption	Total
  Developed Dementia	20	20	21	61
  Did not Develop Dementia	204	622	522	1,348
  Total	224	642	543	1,409

Answer 1

Ho :- developing dementia and low coffee consumption are independent

Ha:- developing dementia and low coffee consumption are dependent

We have given the observed frequency

We need to find expected frequency

Conclusion :- we reject ho , there is not enough evidence to conclude that developing dementia and low coffee consumption are independent