Supplementary Exercise 8.21 of IPS7e
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Note that we have used the term classical for the large-sample CI. The
guidelines for use of different CIs for one proportion are on slide 7L-3.

(a)
We cannot use the large-sample CI because X<15 (and n-X<15). Nor can we use the 
plus four CI because n<10. One could use an "exact" (based on the binomial distribution) 
interval instead.

(b)
We cannot use the large-sample CI because X<15. We can however use the plus four
method because n>>10. 

(c)
Both the large-sample CI and the plus four CI are valid to use. Perhaps the plus
four CI is preferable with the moderate sample size.

(d)
The large-sample CI does not apply because X<15 (and n-X<15). The plus four CI does apply.

(e)
All CI types apply. Perhaps the most natural method is the large-sample CI
(the sample is indeed large).