Patients in 3 age groups who had an unprovoked seizure were studied for 12 months to determine the risk of developing later seizure. The study sample includes 65 participants who were less than 20 years old, 85 participants of ages 20-39 years, and 50 participants of ages 40 years or older. Later seizure is classified into two types - idiopathic or remote symptomatic. As the biostatistician in the study, your analytical plan includes examining whether the later seizure type vary by age group?

	Age Group
Later Seizure Type		20-39	40+	Total
Idiopathic symptomatic	43	65	12	120
remote symptomatic	22	20	38	80
Total	65	85	50	200

1) Using words state the hypothesis comparing differences in proportion among the three age groups.

2) Compute the expected table for the data.

3) Using a contingency table approach, assess if there is any statistically significant difference between the three groups. Use significant level of 0.05 (i.e. 0.95 column of the appendix table 6 below).

4) What is your conclusion?

Table 6: