Section 12.2 Two-Proportion z tests Great Day! It’s Friday!!

Comparing Two Proportions Chapter 12 Section 2 Comparing Two Proportions 2-Proportion Z test – compares the proportion of successes in two independent populations by comparing the difference between the two population proportions, p1 and p2 . (use identifying subscripts when labeling p)

Assumptions for 2 Prop. z Test: 2 independent SRSs N ≥ 10 n Because we do not always know p1 or p2 the statistic that estimates this difference is the difference between the two sample proportions Assumptions for 2 Prop. z Test: 2 independent SRSs N ≥ 10 n (n1)(p̂) ≥ 5 and (n1)(1-p̂) ≥ 5 (n2)(p̂) ≥ 5 and (n2)(1-p̂) ≥ 5

The 2-proportion Z test equation looks like: Z = (everything below p̂1 - p̂2 is underneath the square root symbol) Find Z value on table A and get corresponding P-value. P-value is interpreted the same as on the other significance tests.

 

  Assignment: p.688 & 689 #s 21 and 23