Answer: a) (0.755, 0.925)
Step-by-step explanation:
Let p be the population proportion of 8th graders are involved with some type of after school activity.
As per given , we have
n= 100
sample proportion: 
Significance level : 
Critical z-value :
(using z-value table)
Then, the 98% confidence interval that estimates the proportion of them that are involved in an after school activity will be :-

i.e. 
i.e. 
i.e. 
Hence, the 98% confidence interval that estimates the proportion of them that are involved in an after school activity : a) (0.755, 0.925)