To Perform a Hypothesis Test of Two Population Proportions, the Pooled

To perform a hypothesis test of two population proportions, the pooled estimate of $p$ must be determined. The pooled estimate, $\hat { p }$ , is

A) $\hat { p } = \frac { x _ { 1 } + x _ { 2 } } { n _ { 1 } + n _ { 2 } }$
B) $\hat { \mathrm { p } } = \frac { \mathrm { x } _ { 1 } } { \mathrm { n } _ { 1 } } + \frac { \mathrm { x } _ { 2 } } { \mathrm { n } _ { 2 } }$
C) $\hat { p } = \frac { n _ { 2 } x _ { 1 } + n _ { 1 \times 2 } } { n _ { 1 } + n _ { 2 } }$
D) $\hat { p } = \frac { x _ { 1 } + x _ { 2 } } { n _ { 1 } n _ { 2 } }$ 3 Construct and interpret confidence intervals for the difference between two population proportions.