Step 1 :\( p_1 = \frac{80}{100} = 0.80 \), \( p_2 = \frac{153}{180} = 0.85 \)
Step 2 :\( \hat{p} = \frac{80+153}{100+180} = \frac{233}{280} \approx 0.8321 \)
Step 3 :\( Test\ Statistic = \frac{p_1 - p_2}{\sqrt{\frac{\hat{p}(1-\hat{p})}{n_1} + \frac{\hat{p}(1-\hat{p})}{n_2}}} = \frac{(0.80 - 0.85)}{\sqrt{\frac{(0.8321)(1-0.8321)}{100} + \frac{(0.8321)(1-0.8321)}{180}}} \approx -1.7966 \)