Table 2. Sample-size estimates based on zero Cl⁻ plus isoproterenol (CFTR) response^*.

Treatment Effect (mV)	Total Number of Subjects
	90% Power			80% Power
	Average of Both Nostrils	Most-polarized nostril at Each Visit	Most-polarized nostril at Screening Carried Forward	Average of Both Nostrils	Most-polarized nostril at Each Visit	Most-polarized nostril at Screening Carried Forward
A. Comparison with placebo
−1	854	676	854	638	506	638
−2	216	172	216	162	128	162
−3	98	78	98	74	58	74
−4	56	46	56	42	34	42
−5	38	30	38	28	24	28
B. Within-group comparison **
−1	215	188	215	161	149	161
−2	56	49	56	42	37	42
−3	26	23	26	20	18	20
−4	16	14	16	12	11	12
−5	11	10	11	9	8	9

^*Parts 1 and 2 combined analysis at Day 14.

^**Assume a single-arm study.